huge

.clang-format

@@ -65,7 +65,7 @@ PointerAlignment: Left
 ReferenceAlignment: Left              # New in v13. int &name  ==>  int& name
 ReflowComments: false
 SeparateDefinitionBlocks: Always      # New in v14.
-SortIncludes: true
+SortIncludes: false
 SortUsingDeclarations: true
 SpaceAfterCStyleCast: false
 SpaceAfterLogicalNot: false

.gitignore

@@ -2,6 +2,8 @@
 /lua
 /lua_modules
 /.luarocks
+*.pch
+*.gch
 *.so
 *.o
 .cache/

.luarc.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://raw.githubusercontent.com/LuaLS/vscode-lua/master/setting/schema.json",
-  "runtime.version": "Lua 5.4",
+  "runtime.version": "LuaJIT",
   "runtime.path": [
     "./?/init.lua",
     "./?.lua",

Makefile

@@ -1,56 +1,85 @@
-SRCDIR := .
 CC := $(CROSS)gcc
-CFLAGS := -fPIC -Os
-CXXFLAGS := -I$(SRCDIR)/kiwi -fno-rtti
-F_LTO := -flto=auto
-CXXFLAGS_EXTRA := -pedantic -std=c++14 -Wall $(F_LTO)
-CFLAGS_EXTRA := -pedantic -std=c99 -Wall $(F_LTO)
+CP := cp
+RM := rm
 LIBFLAG := -shared
 LIB_EXT := so
 LUA_INCDIR := /usr/include
 
-ifeq ($(findstring gcc,$(CC)),gcc)
-  CXX := $(subst gcc,g++,$(CC))
-  CXXFLAGS += -std=c++14
-  ifneq ($(SANITIZE),)
-    CFLAGS += -fsanitize=undefined -fsanitize=address
-  endif
+SRCDIR := .
+
+OPTFLAG := -O2
+CCFLAGS += $(OPTFLAG) -fPIC -Wall -fstrict-flex-arrays -fvisibility=hidden -Wformat=2 -Wconversion -Wimplicit-fallthrough
+
+SANITIZE_FLAGS := -fsanitize=undefined -fsanitize=address
+LTO_FLAGS := -flto=auto
+
+ifdef SANITIZE
+	CCFLAGS += $(SANITIZE_FLAGS)
+endif
+ifdef LTO
+	CCFLAGS += $(LTO_FLAGS)
+endif
+
+override CPPFLAGS += -I$(SRCDIR) -I$(SRCDIR)/kiwi -I$(LUA_INCDIR)
+override CXXFLAGS += -std=c++14 -fno-rtti $(CCFLAGS)
+override CFLAGS += -std=c99 $(CCFLAGS)
+
+ifneq ($(filter %gcc,$(CC)),)
+  CXX := $(patsubst %gcc,%g++,$(CC))
+  PCH := ljkiwi.hpp.gch
 else
-ifeq ($(CC),clang)
-  CXX := clang++
-  CXXFLAGS += -std=c++14
-  ifneq ($(SANITIZE),)
-    CFLAGS += -fsanitize=undefined -fsanitize=address
-  endif
-else
-  CXX := $(CC)
+  ifneq ($(filter %clang,$(CC)),)
+    CXX := $(patsubst %clang,%clang++,$(CC))
+    override CXXFLAGS += -pedantic -Wno-c99-extensions
+		PCH := ljkiwi.hpp.pch
 endif
 endif
 
-OBJS := ckiwi.o luakiwi.o
+ifdef LUA
+LUA_VERSION ?= $(lastword $(shell $(LUA) -e "print(_VERSION)"))
+endif
 
-VPATH = $(SRCDIR)/ckiwi $(SRCDIR)/luakiwi
+ifndef LUA_VERSION
+LJKIWI_CKIWI := 1
+else
+  ifneq ($(LUA_VERSION),5.1)
+    LJKIWI_CKIWI :=
+  endif
+endif
 
-all: ckiwi.$(LIB_EXT)
+OBJS := luakiwi.o
+ifdef LJKIWI_CKIWI
+	OBJS += ckiwi.o
+endif
+
+vpath %.cpp $(SRCDIR)/ckiwi $(SRCDIR)/luakiwi
+vpath %.h $(SRCDIR)/ckiwi $(SRCDIR)/luakiwi
+
+all: ljkiwi.$(LIB_EXT)
 
 install:
-	cp -f ckiwi.$(LIB_EXT) $(INST_LIBDIR)/ckiwi.$(LIB_EXT)
-	cp -f kiwi.lua $(INST_LUADIR)/kiwi.lua
+	$(CP) -f ljkiwi.$(LIB_EXT) $(INST_LIBDIR)/ljkiwi.$(LIB_EXT)
+	$(CP) -f kiwi.lua $(INST_LUADIR)/kiwi.lua
 
 clean:
-	rm -f ckiwi.$(LIB_EXT) $(OBJS)
+	$(RM) -f ljkiwi.$(LIB_EXT) $(OBJS) $(PCH)
 
+ckiwi.o: $(PCH) ckiwi.cpp ckiwi.h
+luakiwi.o: $(PCH) luakiwi-int.h luacompat.h
 
-ckiwi.$(LIB_EXT): $(OBJS)
-	$(CXX) $(CXXFLAGS) $(CFLAGS) $(CFLAGS_EXTRA) -I$(SRCDIR)/kiwi $(LIBFLAG) -o $@ $^
+ljkiwi.$(LIB_EXT): $(OBJS)
+	$(CXX) $(CCFLAGS) $(LIBFLAG) -o $@ $(OBJS)
 
-ckiwi.o: ckiwi.h
-luakiwi.o: ckiwi.h luakiwi-int.h luacompat.h
+%.hpp.gch: %.hpp
+	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -x c++-header -o $@ $<
+
+%.hpp.pch: %.hpp
+	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -x c++-header -o $@ $<
 
 %.o: %.c
-	$(CC) -I$(LUA_INCDIR) $(CFLAGS) $(CFLAGS_EXTRA) -c -o $@ $<
+	$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
 
 %.o: %.cpp
-	$(CXX) -I$(LUA_INCDIR) $(CXXFLAGS) $(CFLAGS) $(CXXFLAGS_EXTRA) -c -o $@ $<
+	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c -o $@ $<
 
 .PHONY: all install clean

build.bat

@@ -0,0 +1,2 @@
+cl /nologo  /O2 /W4 /wd4200  /c /D_CRT_SECURE_NO_DEPRECATE /I "C:\Program Files\luarocks\include" /EHs /I kiwi luakiwi\luakiwi.cpp
+link /DLL /out:ckiwi.dll /def:luakiwi.def /LIBPATH:"C:\Program Files\luarocks\lib" luakiwi.obj lua54.lib

ckiwi/ckiwi.cpp

@@ -1,3 +1,4 @@
+#include "ljkiwi.hpp"
 #include "ckiwi.h"
 
 #include <kiwi/kiwi.h>
@@ -5,99 +6,17 @@
 #include <cstdlib>
 #include <cstring>
 
-using namespace kiwi;
+#if defined(__GNUC__) && !defined(LJKIWI_NO_BUILTIN)
+   #define lk_likely(x) (__builtin_expect(((x) != 0), 1))
+   #define lk_unlikely(x) (__builtin_expect(((x) != 0), 0))
+#else
+   #define lk_likely(x) (x)
+   #define lk_unlikely(x) (x)
+#endif
 
 namespace {
 
-template<typename T, typename R, typename... Args>
-inline R make_cref(Args&&... args) {
-   static_assert(
-       sizeof(R) >= sizeof(T),  //NOLINT(bugprone-sizeof-expression)
-       "to_cref: R too small for T"
-   );
-   static_assert(alignof(R) >= alignof(T), "to_cref: R alignment too small for T");
-
-   R cref;
-   new (&cref) T(std::forward<Args>(args)...);
-   return cref;
-}
-
-template<typename... Args>
-inline decltype(auto) make_var_cref(Args&&... args) {
-   return make_cref<Variable, KiwiVarRef>(std::forward<Args>(args)...);
-}
-
-template<typename... Args>
-inline decltype(auto) make_constraint_cref(Args&&... args) {
-   return make_cref<Constraint, KiwiConstraintRef>(std::forward<Args>(args)...);
-}
-
-template<class T, class R>
-class SharedRef {
- private:
-   R& cref_;
-
- public:
-   explicit SharedRef<T, R>(R& cref) : cref_(cref) {}
-
-   static_assert(
-       sizeof(R) >= sizeof(T),  //NOLINT(bugprone-sizeof-expression)
-       "SharedRef<T,CS> CS too small for T"
-   );
-
-   R clone() const {
-      return make_cref<T, R>(cref());
-   }
-
-   void release() {
-      if (cref_) {
-         ptr()->~T();
-         cref_ = nullptr;
-      }
-   }
-
-   T* ptr() {
-      T* p;
-      void* s = &cref_;
-      std::memcpy(&p, &s, sizeof p);  //NOLINT(bugprone-sizeof-expression)
-      return p;
-   }
-
-   const T* const_ptr() const {
-      const T* p;
-      const void* s = &cref_;
-      std::memcpy(&p, &s, sizeof p);  //NOLINT(bugprone-sizeof-expression)
-      return p;
-   }
-
-   const T& cref() const {
-      return *const_ptr();
-   }
-
-   T* operator&() const {
-      return ptr();
-   }
-
-   T* operator->() {
-      return ptr();
-   }
-
-   const T* operator->() const {
-      return const_ptr();
-   }
-
-   operator const T&() const {
-      return cref();
-   }
-
-   explicit operator bool() const {
-      return cref_;
-   }
-};
-
-using ConstraintRef = SharedRef<Constraint, KiwiConstraintRef>;
-using VariableRef = SharedRef<Variable, KiwiVarRef>;
-using ConstVariableRef = const SharedRef<const Variable, const KiwiVarRef>;
+using namespace kiwi;
 
 const KiwiErr* new_error(const KiwiErr* base, const std::exception& ex) {
    if (!std::strcmp(ex.what(), base->message))
@@ -117,18 +36,15 @@ const KiwiErr* new_error(const KiwiErr* base, const std::exception& ex) {
 
 static const constexpr KiwiErr kKiwiErrUnhandledCxxException {
     KiwiErrUnknown,
-    "An unhandled C++ exception occurred."
-};
+    "An unhandled C++ exception occurred."};
 
 static const constexpr KiwiErr kKiwiErrNullObjectArg0 {
     KiwiErrNullObject,
-    "null object passed as argument #0 (self)"
-};
+    "null object passed as argument #0 (self)"};
 
 static const constexpr KiwiErr kKiwiErrNullObjectArg1 {
     KiwiErrNullObject,
-    "null object passed as argument #1"
-};
+    "null object passed as argument #1"};
 
 template<typename F>
 inline const KiwiErr* wrap_err(F&& f) {
@@ -137,49 +53,42 @@ inline const KiwiErr* wrap_err(F&& f) {
    } catch (const UnsatisfiableConstraint& ex) {
       static const constexpr KiwiErr err {
           KiwiErrUnsatisfiableConstraint,
-          "The constraint cannot be satisfied."
-      };
+          "The constraint cannot be satisfied."};
       return &err;
    } catch (const UnknownConstraint& ex) {
       static const constexpr KiwiErr err {
           KiwiErrUnknownConstraint,
-          "The constraint has not been added to the solver."
-      };
+          "The constraint has not been added to the solver."};
       return &err;
 
    } catch (const DuplicateConstraint& ex) {
       static const constexpr KiwiErr err {
           KiwiErrDuplicateConstraint,
-          "The constraint has already been added to the solver."
-      };
+          "The constraint has already been added to the solver."};
       return &err;
 
    } catch (const UnknownEditVariable& ex) {
       static const constexpr KiwiErr err {
           KiwiErrUnknownEditVariable,
-          "The edit variable has not been added to the solver."
-      };
+          "The edit variable has not been added to the solver."};
       return &err;
 
    } catch (const DuplicateEditVariable& ex) {
       static const constexpr KiwiErr err {
           KiwiErrDuplicateEditVariable,
-          "The edit variable has already been added to the solver."
-      };
+          "The edit variable has already been added to the solver."};
       return &err;
 
    } catch (const BadRequiredStrength& ex) {
       static const constexpr KiwiErr err {
           KiwiErrBadRequiredStrength,
-          "A required strength cannot be used in this context."
-      };
+          "A required strength cannot be used in this context."};
       return &err;
 
    } catch (const InternalSolverError& ex) {
       static const constexpr KiwiErr base {
           KiwiErrInternalSolverError,
-          "An internal solver error occurred."
-      };
+          "An internal solver error occurred."};
       return new_error(&base, ex);
    } catch (std::bad_alloc&) {
       static const constexpr KiwiErr err {KiwiErrAlloc, "A memory allocation failed."};
@@ -193,82 +102,96 @@ inline const KiwiErr* wrap_err(F&& f) {
 }
 
 template<typename P, typename R, typename F>
-inline const KiwiErr* wrap_err(P ptr, F&& f) {
-   if (!ptr) {
+inline const KiwiErr* wrap_err(P self, F&& f) {
+   if (lk_unlikely(!self)) {
       return &kKiwiErrNullObjectArg0;
    }
-   return wrap_err([&]() { f(ptr); });
+   return wrap_err([&]() { f(self->solver); });
 }
 
 template<typename P, typename R, typename F>
-inline const KiwiErr* wrap_err(P ptr, R ref, F&& f) {
-   if (!ptr) {
+inline const KiwiErr* wrap_err(P self, R item, F&& f) {
+   if (lk_unlikely(!self)) {
       return &kKiwiErrNullObjectArg0;
-   } else if (!ref) {
+   } else if (lk_unlikely(!item)) {
       return &kKiwiErrNullObjectArg1;
    }
-   return wrap_err([&]() { f(ptr, ref); });
+   return wrap_err([&]() { f(self->solver, *item); });
 }
 
 }  // namespace
 
 extern "C" {
 
-KiwiVarRef kiwi_var_new(const char* name) {
-   return make_var_cref(name ? name : "");
+KiwiTypeInfo kiwi_ti_KiwiVar = {sizeof(KiwiVar), alignof(KiwiVar)};
+KiwiTypeInfo kiwi_ti_KiwiConstraint = {sizeof(KiwiConstraint), alignof(KiwiConstraint)};
+
+void kiwi_var_construct(const char* name, void* mem) {
+   new (mem) KiwiVar {lk_likely(name) ? name : ""};
 }
 
-void kiwi_var_del(KiwiVarRef var) {
-   VariableRef(var).release();
+void kiwi_var_release(KiwiVar* var) {
+   if (lk_likely(var))
+      var->~KiwiVar();
 }
 
-KiwiVarRef kiwi_var_clone(KiwiVarRef var) {
-   return VariableRef(var).clone();
-}
-
-const char* kiwi_var_name(KiwiVarRef var) {
-   const VariableRef self(var);
-   return self ? self->name().c_str() : "(<null>)";
-}
-
-void kiwi_var_set_name(KiwiVarRef var, const char* name) {
-   VariableRef self(var);
-   if (self)
-      self->setName(name);
-}
-
-double kiwi_var_value(KiwiVarRef var) {
-   const VariableRef self(var);
-   return self ? self->value() : std::numeric_limits<double>::quiet_NaN();
-}
-
-void kiwi_var_set_value(KiwiVarRef var, double value) {
-   VariableRef self(var);
-   if (self)
-      self->setValue(value);
-}
-
-bool kiwi_var_eq(KiwiVarRef var, KiwiVarRef other) {
-   ConstVariableRef self(var);  // const defect in upstream
-   const VariableRef other_ref(other);
-
-   return self && other_ref && self->equals(other_ref);
-}
-
-void kiwi_expression_del_vars(KiwiExpression* expr) {
-   if (!expr)
-      return;
-
-   for (auto* t = expr->terms; t != expr->terms + expr->term_count; ++t) {
-      VariableRef(t->var).release();
+void kiwi_var_retain(KiwiVar* var) {
+   if (lk_likely(var)) {
+      alignas(KiwiVar) unsigned char buf[sizeof(KiwiVar)];
+      new (buf) KiwiVar(*var);
    }
 }
 
-KiwiConstraintRef kiwi_constraint_new(
+const char* kiwi_var_name(const KiwiVar* var) {
+   return lk_likely(var) ? var->name().c_str() : "(<null>)";
+}
+
+void kiwi_var_set_name(KiwiVar* var, const char* name) {
+   if (lk_likely(var))
+      var->setName(name);
+}
+
+double kiwi_var_value(const KiwiVar* var) {
+   return lk_likely(var) ? var->value() : std::numeric_limits<double>::quiet_NaN();
+}
+
+void kiwi_var_set_value(KiwiVar* var, double value) {
+   if (lk_likely(var))
+      var->setValue(value);
+}
+
+bool kiwi_var_eq(const KiwiVar* var, const KiwiVar* other) {
+   return lk_likely(var && other) && var->equals(*other);
+}
+
+void kiwi_expression_retain(KiwiExpression* expr) {
+   if (lk_unlikely(!expr))
+      return;
+   alignas(KiwiVar) unsigned char buf[sizeof(KiwiVar)];
+   for (auto* t = expr->terms_; t != expr->terms_ + expr->term_count; ++t) {
+      new (buf) KiwiVar(*t->var);
+   }
+}
+
+void kiwi_expression_destroy(KiwiExpression* expr) {
+   if (lk_unlikely(!expr))
+      return;
+
+   if (expr->owner) {
+      expr->owner->~KiwiConstraint();
+   } else {
+      for (auto* t = expr->terms_; t != expr->terms_ + expr->term_count; ++t) {
+         t->var->~KiwiVar();
+      }
+   }
+}
+
+void kiwi_constraint_construct(
     const KiwiExpression* lhs,
     const KiwiExpression* rhs,
     enum KiwiRelOp op,
-    double strength
+    double strength,
+    void* mem
 ) {
    if (strength < 0.0) {
       strength = kiwi::strength::required;
@@ -278,69 +201,69 @@ KiwiConstraintRef kiwi_constraint_new(
    terms.reserve((lhs ? lhs->term_count : 0) + (rhs ? rhs->term_count : 0));
 
    if (lhs) {
-      for (auto* t = lhs->terms; t != lhs->terms + lhs->term_count; ++t) {
-         ConstVariableRef var(t->var);
-         if (var)
-            terms.emplace_back(var.cref(), t->coefficient);
+      for (auto* t = lhs->terms_; t != lhs->terms_ + lhs->term_count; ++t) {
+         if (t->var)
+            terms.emplace_back(*t->var, t->coefficient);
       }
    }
    if (rhs) {
-      for (auto* t = rhs->terms; t != rhs->terms + rhs->term_count; ++t) {
-         ConstVariableRef var(t->var);
-         if (var)
-            terms.emplace_back(var.cref(), -t->coefficient);
+      for (auto* t = rhs->terms_; t != rhs->terms_ + rhs->term_count; ++t) {
+         if (t->var)
+            terms.emplace_back(*t->var, -t->coefficient);
       }
    }
 
-   return make_constraint_cref(
+   new (mem) Constraint(
        Expression(std::move(terms), (lhs ? lhs->constant : 0.0) - (rhs ? rhs->constant : 0.0)),
        static_cast<RelationalOperator>(op),
        strength
    );
 }
 
-void kiwi_constraint_del(KiwiConstraintRef constraint) {
-   ConstraintRef(constraint).release();
+void kiwi_constraint_release(KiwiConstraint* c) {
+   if (lk_likely(c))
+      c->~KiwiConstraint();
 }
 
-KiwiConstraintRef kiwi_constraint_clone(KiwiConstraintRef constraint) {
-   return ConstraintRef(constraint).clone();
-}
-
-double kiwi_constraint_strength(KiwiConstraintRef constraint) {
-   const ConstraintRef self(constraint);
-   return self ? self->strength() : std::numeric_limits<double>::quiet_NaN();
-}
-
-enum KiwiRelOp kiwi_constraint_op(KiwiConstraintRef constraint) {
-   const ConstraintRef self(constraint);
-   return self ? static_cast<KiwiRelOp>(self->op()) : KiwiRelOp::KIWI_OP_EQ;
-}
-
-bool kiwi_constraint_violated(KiwiConstraintRef constraint) {
-   const ConstraintRef self(constraint);
-   return self ? self->violated() : 0;
-}
-
-int kiwi_constraint_expression(KiwiConstraintRef constraint, KiwiExpression* out, int out_size) {
-   const ConstraintRef self(constraint);
-   if (!self)
-      return 0;
-   const auto& expr = self->expression();
-   const auto& terms = expr.terms();
-   const int n_terms = terms.size();
-   if (!out || out_size < n_terms)
-      return n_terms;
-
-   auto* p = out->terms;
-   for (const auto& t : terms) {
-      *p = KiwiTerm {make_var_cref(t.variable()), t.coefficient()};
-      ++p;
+void kiwi_constraint_retain(KiwiConstraint* c) {
+   if (lk_likely(c)) {
+      alignas(KiwiConstraint) unsigned char buf[sizeof(KiwiConstraint)];
+      new (buf) KiwiConstraint(*c);
    }
-   out->term_count = p - out->terms;
-   out->constant = expr.constant();
+}
 
-   return n_terms;
+double kiwi_constraint_strength(const KiwiConstraint* c) {
+   return lk_likely(c) ? c->strength() : std::numeric_limits<double>::quiet_NaN();
+}
+
+enum KiwiRelOp kiwi_constraint_op(const KiwiConstraint* c) {
+   return lk_likely(c) ? static_cast<KiwiRelOp>(c->op()) : KiwiRelOp::KIWI_OP_EQ;
+}
+
+bool kiwi_constraint_violated(const KiwiConstraint* c) {
+   return lk_likely(c) ? c->violated() : false;
+}
+
+int kiwi_constraint_expression(KiwiConstraint* c, KiwiExpression* out, int out_size) {
+   if (lk_unlikely(!c))
+      return 0;
+
+   const auto& expr = c->expression();
+   const auto& terms = expr.terms();
+   const auto term_count = static_cast<int>(terms.size());
+   if (!out || out_size < term_count)
+      return term_count;
+
+   for (int i = 0; i < term_count; ++i) {
+      out->terms_[i].var = const_cast<KiwiVar*>(&terms[i].variable());
+      out->terms_[i].coefficient = terms[i].coefficient();
+   }
+   out->constant = expr.constant();
+   out->term_count = term_count;
+   out->owner = c;
+   kiwi_constraint_retain(c);
+
+   return term_count;
 }
 
 struct KiwiSolver {
@@ -348,79 +271,80 @@ struct KiwiSolver {
    Solver solver;
 };
 
-KiwiSolver* kiwi_solver_new(unsigned error_mask) {
-   return new KiwiSolver {error_mask};
+KiwiTypeInfo kiwi_ti_KiwiSolver = {sizeof(KiwiSolver), alignof(KiwiSolver)};
+
+void kiwi_solver_construct(unsigned error_mask, void* mem) {
+   new (mem) KiwiSolver {error_mask};
 }
 
-void kiwi_solver_del(KiwiSolver* s) {
-   if (s)
-      delete s;
+void kiwi_solver_destroy(KiwiSolver* s) {
+   if (lk_likely(s))
+      s->~KiwiSolver();
 }
 
-const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* s, KiwiConstraintRef constraint) {
-   return wrap_err(s, ConstraintRef(constraint), [](auto* s, const auto c) {
-      s->solver.addConstraint(c);
-   });
+unsigned kiwi_solver_get_error_mask(const KiwiSolver* s) {
+   return lk_likely(s) ? s->error_mask : 0;
 }
 
-const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* s, KiwiConstraintRef constraint) {
-   return wrap_err(s, ConstraintRef(constraint), [](auto* s, const auto c) {
-      s->solver.removeConstraint(c);
-   });
+void kiwi_solver_set_error_mask(KiwiSolver* s, unsigned mask) {
+   if (lk_likely(s))
+      s->error_mask = mask;
 }
 
-bool kiwi_solver_has_constraint(const KiwiSolver* s, KiwiConstraintRef constraint) {
-   ConstraintRef c(constraint);
-   if (!s || !c)
+const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* s, const KiwiConstraint* constraint) {
+   return wrap_err(s, constraint, [](auto& s, const auto& c) { s.addConstraint(c); });
+}
+
+const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* s, const KiwiConstraint* constraint) {
+   return wrap_err(s, constraint, [](auto& s, const auto& c) { s.removeConstraint(c); });
+}
+
+bool kiwi_solver_has_constraint(const KiwiSolver* s, const KiwiConstraint* constraint) {
+   if (lk_unlikely(!s || !constraint))
       return 0;
-   return s->solver.hasConstraint(c);
+   return s->solver.hasConstraint(*constraint);
 }
 
-const KiwiErr* kiwi_solver_add_edit_var(KiwiSolver* s, KiwiVarRef var, double strength) {
-   return wrap_err(s, VariableRef(var), [strength](auto* s, const auto v) {
-      s->solver.addEditVariable(v, strength);
+const KiwiErr* kiwi_solver_add_edit_var(KiwiSolver* s, const KiwiVar* var, double strength) {
+   return wrap_err(s, var, [strength](auto& s, const auto& v) {
+      s.addEditVariable(v, strength);
    });
 }
 
-const KiwiErr* kiwi_solver_remove_edit_var(KiwiSolver* s, KiwiVarRef var) {
-   return wrap_err(s, VariableRef(var), [](auto* s, const auto v) {
-      s->solver.removeEditVariable(v);
-   });
+const KiwiErr* kiwi_solver_remove_edit_var(KiwiSolver* s, const KiwiVar* var) {
+   return wrap_err(s, var, [](auto& s, const auto& v) { s.removeEditVariable(v); });
 }
 
-bool kiwi_solver_has_edit_var(const KiwiSolver* s, KiwiVarRef var) {
-   VariableRef v(var);
-   if (!s || !v)
+bool kiwi_solver_has_edit_var(const KiwiSolver* s, const KiwiVar* var) {
+   if (lk_unlikely(!s || !var))
       return 0;
-   return s->solver.hasEditVariable(v);
+   return s->solver.hasEditVariable(*var);
 }
 
-const KiwiErr* kiwi_solver_suggest_value(KiwiSolver* s, KiwiVarRef var, double value) {
-   return wrap_err(s, VariableRef(var), [value](auto* s, const auto v) {
-      s->solver.suggestValue(v, value);
-   });
+const KiwiErr* kiwi_solver_suggest_value(KiwiSolver* s, const KiwiVar* var, double value) {
+   return wrap_err(s, var, [value](auto& s, const auto& v) { s.suggestValue(v, value); });
 }
 
 void kiwi_solver_update_vars(KiwiSolver* s) {
-   if (s)
+   if (lk_likely(s))
       s->solver.updateVariables();
 }
 
 void kiwi_solver_reset(KiwiSolver* s) {
-   if (s)
+   if (lk_likely(s))
       s->solver.reset();
 }
 
 void kiwi_solver_dump(const KiwiSolver* s) {
-   if (s)
+   if (lk_likely(s))
       s->solver.dump();
 }
 
 char* kiwi_solver_dumps(const KiwiSolver* s) {
-   if (!s)
+   if (lk_unlikely(!s))
       return nullptr;
 
-   const auto str = s->solver.dumps();  // upstream library defect
+   const auto& str = s->solver.dumps();
    const auto buf_size = str.size() + 1;
    auto* buf = static_cast<char*>(std::malloc(buf_size));
    if (!buf)

ckiwi/ckiwi.h

@@ -1,13 +1,38 @@
-#ifndef KIWI_CKIWI_H_
-#define KIWI_CKIWI_H_
+#ifndef LJKIWI_CKIWI_H_
+#define LJKIWI_CKIWI_H_
 
-#ifdef __cplusplus
-extern "C" {
+#if !defined(_MSC_VER) || _MSC_VER >= 1900
+   #undef LJKIWI_USE_FAM_1
 #else
-   #include <stdbool.h>
+   #define LJKIWI_USE_FAM_1
 #endif
 
-#define KIWI_REF_ISNULL(ref) ((ref).impl_ == NULL)
+#ifdef __cplusplus
+
+namespace kiwi {
+class Variable;
+class Constraint;
+}  // namespace kiwi
+
+extern "C" {
+
+typedef kiwi::Variable KiwiVar;
+typedef kiwi::Constraint KiwiConstraint;
+#else
+typedef struct KiwiVar KiwiVar;
+typedef struct KiwiConstraint KiwiConstraint;
+#endif
+
+typedef struct KiwiTypeInfo {
+   unsigned size;
+   unsigned align;
+} KiwiTypeInfo;
+
+#if __GNUC__
+   #pragma GCC visibility push(default)
+#endif
+
+extern KiwiTypeInfo kiwi_ti_KiwiVar, kiwi_ti_KiwiConstraint, kiwi_ti_KiwiSolver;
 
 // LuaJIT start
 enum KiwiErrKind {
@@ -26,18 +51,24 @@ enum KiwiErrKind {
 
 enum KiwiRelOp { KIWI_OP_LE, KIWI_OP_GE, KIWI_OP_EQ };
 
-typedef struct KiwiVarRefType* KiwiVarRef;
-typedef struct KiwiConstraintRefType* KiwiConstraintRef;
-
 typedef struct KiwiTerm {
-   KiwiVarRef var;
+   KiwiVar* var;
    double coefficient;
 } KiwiTerm;
 
 typedef struct KiwiExpression {
    double constant;
    int term_count;
-   KiwiTerm terms[1];  // LuaJIT: struct KiwiTerm terms_[?];
+   KiwiConstraint* owner;
+
+#if defined(LJKIWI_LUAJIT_DEF)
+   KiwiTerm terms_[?];
+#elif defined(LJKIWI_USE_FAM_1)
+   KiwiTerm terms_[1];  // LuaJIT: struct KiwiTerm terms_[?];
+#else
+   KiwiTerm terms_[];
+#endif
+
 } KiwiExpression;
 
 typedef struct KiwiErr {
@@ -46,56 +77,63 @@ typedef struct KiwiErr {
    bool must_free;
 } KiwiErr;
 
-typedef struct KiwiSolver
-    KiwiSolver;  // LuaJIT: typedef struct { unsigned error_mask; } KiwiSolver;
-KiwiVarRef kiwi_var_new(const char* name);
-void kiwi_var_del(KiwiVarRef var);
-KiwiVarRef kiwi_var_clone(KiwiVarRef var);
+struct KiwiSolver;
 
-const char* kiwi_var_name(KiwiVarRef var);
-void kiwi_var_set_name(KiwiVarRef var, const char* name);
-double kiwi_var_value(KiwiVarRef var);
-void kiwi_var_set_value(KiwiVarRef var, double value);
-bool kiwi_var_eq(KiwiVarRef var, KiwiVarRef other);
+void kiwi_var_construct(const char* name, void* mem);
+void kiwi_var_release(KiwiVar* var);
+void kiwi_var_retain(KiwiVar* var);
 
-void kiwi_expression_del_vars(KiwiExpression* expr);
+const char* kiwi_var_name(const KiwiVar* var);
+void kiwi_var_set_name(KiwiVar* var, const char* name);
+double kiwi_var_value(const KiwiVar* var);
+void kiwi_var_set_value(KiwiVar* var, double value);
+bool kiwi_var_eq(const KiwiVar* var, const KiwiVar* other);
 
-KiwiConstraintRef kiwi_constraint_new(
+void kiwi_expression_retain(KiwiExpression* expr);
+void kiwi_expression_destroy(KiwiExpression* expr);
+
+void kiwi_constraint_construct(
     const KiwiExpression* lhs,
     const KiwiExpression* rhs,
     enum KiwiRelOp op,
-    double strength
+    double strength,
+    void* mem
 );
-void kiwi_constraint_del(KiwiConstraintRef constraint);
-KiwiConstraintRef kiwi_constraint_clone(KiwiConstraintRef constraint);
+void kiwi_constraint_release(KiwiConstraint* c);
+void kiwi_constraint_retain(KiwiConstraint* c);
 
-double kiwi_constraint_strength(KiwiConstraintRef constraint);
-enum KiwiRelOp kiwi_constraint_op(KiwiConstraintRef constraint);
-bool kiwi_constraint_violated(KiwiConstraintRef constraint);
-int kiwi_constraint_expression(KiwiConstraintRef constraint, KiwiExpression* out, int out_size);
+double kiwi_constraint_strength(const KiwiConstraint* c);
+enum KiwiRelOp kiwi_constraint_op(const KiwiConstraint* c);
+bool kiwi_constraint_violated(const KiwiConstraint* c);
+int kiwi_constraint_expression(KiwiConstraint* c, KiwiExpression* out, int out_size);
 
-KiwiSolver* kiwi_solver_new(unsigned error_mask);
-void kiwi_solver_del(KiwiSolver* s);
+void kiwi_solver_construct(unsigned error_mask, void* mem);
+void kiwi_solver_destroy(KiwiSolver* s);
+unsigned kiwi_solver_get_error_mask(const KiwiSolver* s);
+void kiwi_solver_set_error_mask(KiwiSolver* s, unsigned mask);
 
-const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* sp, KiwiConstraintRef constraint);
-const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* sp, KiwiConstraintRef constraint);
-bool kiwi_solver_has_constraint(const KiwiSolver* sp, KiwiConstraintRef constraint);
-const KiwiErr* kiwi_solver_add_edit_var(KiwiSolver* sp, KiwiVarRef var, double strength);
-const KiwiErr* kiwi_solver_remove_edit_var(KiwiSolver* sp, KiwiVarRef var);
-bool kiwi_solver_has_edit_var(const KiwiSolver* sp, KiwiVarRef var);
-const KiwiErr* kiwi_solver_suggest_value(KiwiSolver* sp, KiwiVarRef var, double value);
+const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* s, const KiwiConstraint* constraint);
+const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* s, const KiwiConstraint* constraint);
+bool kiwi_solver_has_constraint(const KiwiSolver* s, const KiwiConstraint* constraint);
+const KiwiErr* kiwi_solver_add_edit_var(KiwiSolver* s, const KiwiVar* var, double strength);
+const KiwiErr* kiwi_solver_remove_edit_var(KiwiSolver* s, const KiwiVar* var);
+bool kiwi_solver_has_edit_var(const KiwiSolver* s, const KiwiVar* var);
+const KiwiErr* kiwi_solver_suggest_value(KiwiSolver* s, const KiwiVar* var, double value);
 void kiwi_solver_update_vars(KiwiSolver* sp);
 void kiwi_solver_reset(KiwiSolver* sp);
 void kiwi_solver_dump(const KiwiSolver* sp);
 char* kiwi_solver_dumps(const KiwiSolver* sp);
-
 // LuaJIT end
 
+#if __GNUC__
+   #pragma GCC visibility pop
+#endif
+
 #ifdef __cplusplus
-}
+}  // extern "C"
 #endif
 
 // Local Variables:
 // mode: c++
 // End:
-#endif  // KIWI_CKIWI_H_
+#endif  // LJKIWI_CKIWI_H_

kiwi-scm-1.rockspec

@@ -1,15 +1,15 @@
 rockspec_format = "3.0"
-package = "ljkiwi"
+package = "kiwi"
 version = "scm-1"
 source = {
    url = "git+https://github.com/jkl1337/ljkiwi",
 }
 description = {
-   summary = "A LuaJIT FFI binding for the Kiwi constraint solver.",
+   summary = "LuaJIT FFI and Lua binding for the Kiwi constraint solver.",
    detailed = [[
-      ljkiwi is a LuaJIT FFI binding for the Kiwi constraint solver. Kiwi is a fast
-      implementation of the Cassowary constraint solving algorithm. ljkiwi provides
-      reasonably efficient bindings using the LuaJIT FFI.]],
+      kiwi is a LuaJIT FFI and Lua binding for the Kiwi constraint solver. Kiwi is a fast
+      implementation of the Cassowary constraint solving algorithm. kiwi provides
+      reasonably efficient bindings using the LuaJIT FFI and convential Lua C bindings.]],
    license = "MIT",
    issues_url = "https://github.com/jkl1337/ljkiwi/issues",
    maintainer = "John Luebs",
@@ -21,6 +21,7 @@ dependencies = {
 build = {
    type = "make",
    build_variables = {
+      LUA = "$(LUA)",
       CFLAGS = "$(CFLAGS)",
       LUA_INCDIR = "$(LUA_INCDIR)",
       LIBFLAG = "$(LIBFLAG)",

kiwi.lua

@@ -4,20 +4,48 @@ local ffi
 do
    local ffi_loader = package.preload["ffi"]
    if ffi_loader == nil then
-      return require("ckiwi")
+      return require("ljkiwi")
    end
    ffi = ffi_loader() --[[@as ffilib]]
 end
 
 local kiwi = {}
 
-local ckiwi
+local ljkiwi
 do
-   local cpath, err = package.searchpath("ckiwi", package.cpath)
+   local cpath, err = package.searchpath("ljkiwi", package.cpath)
    if cpath == nil then
-      error("kiwi dynamic library 'ckiwi' not found\n" .. err)
+      error("kiwi dynamic library 'ljkiwi' not found\n" .. err)
    end
-   ckiwi = ffi.load(cpath)
+   ljkiwi = ffi.load(cpath)
+end
+kiwi.ljkiwi = ljkiwi
+
+ffi.cdef([[
+void free(void *);
+
+typedef struct KiwiTypeInfo {
+unsigned size;
+unsigned align;
+} KiwiTypeInfo;
+
+extern KiwiTypeInfo kiwi_ti_KiwiVar, kiwi_ti_KiwiConstraint, kiwi_ti_KiwiSolver;
+
+]])
+
+for _, t in ipairs({ "KiwiVar", "KiwiConstraint", "KiwiSolver" }) do
+   local tinfo = ljkiwi[("kiwi_ti_%s"):format(t)] --[[@as any]]
+   ffi.cdef(
+      [[
+typedef struct $ {
+   unsigned char b_[$];
+} __attribute__((aligned($))) $;
+]],
+      t,
+      tinfo.size,
+      tinfo.align,
+      t
+   )
 end
 
 ffi.cdef([[
@@ -37,17 +65,15 @@ enum KiwiErrKind {
 
 enum KiwiRelOp { LE, GE, EQ };
 
-typedef struct KiwiVarRefType* KiwiVarRef;
-typedef struct KiwiConstraintRefType* KiwiConstraintRef;
-
 typedef struct KiwiTerm {
-   KiwiVarRef var;
+   KiwiVar* var;
    double coefficient;
 } KiwiTerm;
 
 typedef struct KiwiExpression {
    double constant;
    int term_count;
+   KiwiConstraint* owner;
    KiwiTerm terms_[?];
 } KiwiExpression;
 
@@ -57,49 +83,52 @@ typedef struct KiwiErr {
    bool must_free;
 } KiwiErr;
 
-typedef struct KiwiSolver { unsigned error_mask_; } KiwiSolver;
+struct KiwiSolver;
 
-KiwiVarRef kiwi_var_new(const char* name);
-void kiwi_var_del(KiwiVarRef var);
-KiwiVarRef kiwi_var_clone(KiwiVarRef var);
+void kiwi_var_construct(const char* name, void* mem);
+void kiwi_var_release(KiwiVar* var);
+void kiwi_var_retain(KiwiVar* var);
 
-const char* kiwi_var_name(KiwiVarRef var);
-void kiwi_var_set_name(KiwiVarRef var, const char* name);
-double kiwi_var_value(KiwiVarRef var);
-void kiwi_var_set_value(KiwiVarRef var, double value);
-bool kiwi_var_eq(KiwiVarRef var, KiwiVarRef other);
+const char* kiwi_var_name(const KiwiVar* var);
+void kiwi_var_set_name(KiwiVar* var, const char* name);
+double kiwi_var_value(const KiwiVar* var);
+void kiwi_var_set_value(KiwiVar* var, double value);
+bool kiwi_var_eq(const KiwiVar* var, const KiwiVar* other);
 
-void kiwi_expression_del_vars(KiwiExpression* expr);
+void kiwi_expression_retain(KiwiExpression* expr);
+void kiwi_expression_destroy(KiwiExpression* expr);
 
-KiwiConstraintRef kiwi_constraint_new(
+void kiwi_constraint_construct(
     const KiwiExpression* lhs,
     const KiwiExpression* rhs,
     enum KiwiRelOp op,
-    double strength
+    double strength,
+    void* mem
 );
-void kiwi_constraint_del(KiwiConstraintRef constraint);
+void kiwi_constraint_release(KiwiConstraint* c);
+void kiwi_constraint_retain(KiwiConstraint* c);
 
-double kiwi_constraint_strength(KiwiConstraintRef constraint);
-enum KiwiRelOp kiwi_constraint_op(KiwiConstraintRef constraint);
-bool kiwi_constraint_violated(KiwiConstraintRef constraint);
-int kiwi_constraint_expression(KiwiConstraintRef constraint, KiwiExpression* out, int out_size);
+double kiwi_constraint_strength(const KiwiConstraint* c);
+enum KiwiRelOp kiwi_constraint_op(const KiwiConstraint* c);
+bool kiwi_constraint_violated(const KiwiConstraint* c);
+int kiwi_constraint_expression(KiwiConstraint* c, KiwiExpression* out, int out_size);
 
-KiwiSolver* kiwi_solver_new(unsigned error_mask);
-void kiwi_solver_del(KiwiSolver* s);
+void kiwi_solver_construct(unsigned error_mask, void* mem);
+void kiwi_solver_destroy(KiwiSolver* s);
+unsigned kiwi_solver_get_error_mask(const KiwiSolver* s);
+void kiwi_solver_set_error_mask(KiwiSolver* s, unsigned mask);
 
-const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* sp, KiwiConstraintRef constraint);
-const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* sp, KiwiConstraintRef constraint);
-bool kiwi_solver_has_constraint(const KiwiSolver* sp, KiwiConstraintRef constraint);
-const KiwiErr* kiwi_solver_add_edit_var(KiwiSolver* sp, KiwiVarRef var, double strength);
-const KiwiErr* kiwi_solver_remove_edit_var(KiwiSolver* sp, KiwiVarRef var);
-bool kiwi_solver_has_edit_var(const KiwiSolver* sp, KiwiVarRef var);
-const KiwiErr* kiwi_solver_suggest_value(KiwiSolver* sp, KiwiVarRef var, double value);
+const KiwiErr* kiwi_solver_add_constraint(KiwiSolver* s, const KiwiConstraint* constraint);
+const KiwiErr* kiwi_solver_remove_constraint(KiwiSolver* s, const KiwiConstraint* constraint);
+bool kiwi_solver_has_constraint(const KiwiSolver* s, const KiwiConstraint* constraint);
+const KiwiErr* kiwi_solver_add_edit_var(KiwiSolver* s, const KiwiVar* var, double strength);
+const KiwiErr* kiwi_solver_remove_edit_var(KiwiSolver* s, const KiwiVar* var);
+bool kiwi_solver_has_edit_var(const KiwiSolver* s, const KiwiVar* var);
+const KiwiErr* kiwi_solver_suggest_value(KiwiSolver* s, const KiwiVar* var, double value);
 void kiwi_solver_update_vars(KiwiSolver* sp);
 void kiwi_solver_reset(KiwiSolver* sp);
 void kiwi_solver_dump(const KiwiSolver* sp);
 char* kiwi_solver_dumps(const KiwiSolver* sp);
-
-void free(void *);
 ]])
 
 local strformat = string.format
@@ -159,7 +188,7 @@ do
    end
 end
 
-local Var = ffi.typeof("struct KiwiVarRefType") --[[@as kiwi.Var]]
+local Var = ffi.typeof("struct KiwiVar") --[[@as kiwi.Var]]
 kiwi.Var = Var
 
 function kiwi.is_var(o)
@@ -173,14 +202,14 @@ function kiwi.is_term(o)
    return ffi_istype(Term, o)
 end
 
-local Expression = ffi.typeof("struct KiwiExpression") --[[@as kiwi.Expression]]
+local Expression = ffi.typeof("KiwiExpression") --[[@as kiwi.Expression]]
 kiwi.Expression = Expression
 
 function kiwi.is_expression(o)
    return ffi_istype(Expression, o)
 end
 
-local Constraint = ffi.typeof("struct KiwiConstraintRefType") --[[@as kiwi.Constraint]]
+local Constraint = ffi.typeof("KiwiConstraint") --[[@as kiwi.Constraint]]
 kiwi.Constraint = Constraint
 
 function kiwi.is_constraint(o)
@@ -192,18 +221,19 @@ end
 ---@param coeff number?
 ---@nodiscard
 local function add_expr_term(expr, var, coeff)
-   local ret = ffi_gc(ffi_new(Expression, expr.term_count + 1), ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
+   local ret = ffi_gc(ffi_new(Expression, expr.term_count + 1), ljkiwi.kiwi_expression_destroy) --[[@as kiwi.Expression]]
    for i = 0, expr.term_count - 1 do
       local st = expr.terms_[i] --[[@as kiwi.Term]]
       local dt = ret.terms_[i] --[[@as kiwi.Term]]
-      dt.var = ckiwi.kiwi_var_clone(st.var)
+      dt.var = st.var
       dt.coefficient = st.coefficient
    end
    local dt = ret.terms_[expr.term_count]
-   dt.var = ckiwi.kiwi_var_clone(var)
+   dt.var = var
    dt.coefficient = coeff or 1.0
    ret.constant = expr.constant
    ret.term_count = expr.term_count + 1
+   ljkiwi.kiwi_expression_retain(ret)
    return ret
 end
 
@@ -212,12 +242,13 @@ end
 ---@param coeff number?
 ---@nodiscard
 local function new_expr_one(constant, var, coeff)
-   local ret = ffi_gc(ffi_new(Expression, 1), ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
+   local ret = ffi_gc(ffi_new(Expression, 1), ljkiwi.kiwi_expression_destroy) --[[@as kiwi.Expression]]
    local dt = ret.terms_[0]
-   dt.var = ckiwi.kiwi_var_clone(var)
+   dt.var = var
    dt.coefficient = coeff or 1.0
    ret.constant = constant
    ret.term_count = 1
+   ljkiwi.kiwi_var_retain(var)
    return ret
 end
 
@@ -228,15 +259,16 @@ end
 ---@param coeff2 number?
 ---@nodiscard
 local function new_expr_pair(constant, var1, var2, coeff1, coeff2)
-   local ret = ffi_gc(ffi_new(Expression, 2), ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
+   local ret = ffi_gc(ffi_new(Expression, 2), ljkiwi.kiwi_expression_destroy) --[[@as kiwi.Expression]]
    local dt = ret.terms_[0]
-   dt.var = ckiwi.kiwi_var_clone(var1)
+   dt.var = var1
    dt.coefficient = coeff1 or 1.0
    dt = ret.terms_[1]
-   dt.var = ckiwi.kiwi_var_clone(var2)
+   dt.var = var2
    dt.coefficient = coeff2 or 1.0
    ret.constant = constant
    ret.term_count = 2
+   ljkiwi.kiwi_expression_retain(ret)
    return ret
 end
 
@@ -311,7 +343,9 @@ local function rel(lhs, rhs, op, strength)
       op_error(lhs, rhs, OP_NAMES[op])
    end
 
-   return ffi_gc(ckiwi.kiwi_constraint_new(el, er, op, strength or REQUIRED), ckiwi.kiwi_constraint_del) --[[@as kiwi.Constraint]]
+   local c = ffi_new(Constraint)
+   ljkiwi.kiwi_constraint_construct(el, er, op, strength or REQUIRED, c)
+   return ffi_gc(c, ljkiwi.kiwi_constraint_release) --[[@as kiwi.Constraint]]
 end
 
 --- Define a constraint with expressions as `a <= b`.
@@ -357,22 +391,22 @@ do
 
       --- Change the name of the variable.
       ---@type fun(self: kiwi.Var, name: string)
-      set_name = ckiwi.kiwi_var_set_name,
+      set_name = ljkiwi.kiwi_var_set_name,
 
       --- Get the current value of the variable.
       ---@type fun(self: kiwi.Var): number
-      value = ckiwi.kiwi_var_value,
+      value = ljkiwi.kiwi_var_value,
 
       --- Set the value of the variable.
       ---@type fun(self: kiwi.Var, value: number)
-      set = ckiwi.kiwi_var_set_value,
+      set = ljkiwi.kiwi_var_set_value,
    }
 
    --- Get the name of the variable.
    ---@return string
    ---@nodiscard
    function Var_cls:name()
-      return ffi_string(ckiwi.kiwi_var_name(self))
+      return ffi_string(ljkiwi.kiwi_var_name(self))
    end
 
    --- Create a term from this variable.
@@ -397,7 +431,9 @@ do
    }
 
    function Var_mt:__new(name)
-      return ffi_gc(ckiwi.kiwi_var_new(name), ckiwi.kiwi_var_del)
+      local v = ffi_new(self)
+      ljkiwi.kiwi_var_construct(name, v)
+      return ffi_gc(v, ljkiwi.kiwi_var_release)
    end
 
    function Var_mt.__mul(a, b)
@@ -441,6 +477,10 @@ do
       return a + -b
    end
 
+   function Var_mt:__eq(other)
+      return ljkiwi.kiwi_var_eq(self, other)
+   end
+
    function Var_mt:__tostring()
       return self:name() .. "(" .. self:value() .. ")"
    end
@@ -482,11 +522,13 @@ do
    local Term_mt = { __index = Term_cls }
 
    local function term_gc(term)
-      ckiwi.kiwi_var_del(term.var)
+      ljkiwi.kiwi_var_release(term.var)
    end
 
    function Term_mt.__new(T, var, coefficient)
-      return ffi_gc(ffi_new(T, ckiwi.kiwi_var_clone(var), coefficient or 1.0), term_gc)
+      local t = ffi_gc(ffi_new(T, var, coefficient or 1.0), term_gc)
+      ljkiwi.kiwi_var_retain(var)
+      return t
    end
 
    function Term_mt.__mul(a, b)
@@ -542,6 +584,7 @@ do
    ---@class kiwi.Expression: ffi.cdata*
    ---@overload fun(constant: number, ...: kiwi.Term): kiwi.Expression
    ---@field constant number
+   ---@field package owner ffi.cdata*
    ---@field package term_count number
    ---@field package terms_ ffi.cdata*
    ---@operator mul(number): kiwi.Expression
@@ -559,15 +602,16 @@ do
    ---@param constant number
    ---@nodiscard
    local function mul_expr_coeff(expr, constant)
-      local ret = ffi_gc(ffi_new(Expression, expr.term_count), ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
+      local ret = ffi_gc(ffi_new(Expression, expr.term_count), ljkiwi.kiwi_expression_destroy) --[[@as kiwi.Expression]]
       for i = 0, expr.term_count - 1 do
          local st = expr.terms_[i] --[[@as kiwi.Term]]
          local dt = ret.terms_[i] --[[@as kiwi.Term]]
-         dt.var = ckiwi.kiwi_var_clone(st.var)
+         dt.var = st.var
          dt.coefficient = st.coefficient * constant
       end
       ret.constant = expr.constant * constant
       ret.term_count = expr.term_count
+      ljkiwi.kiwi_expression_retain(ret)
       return ret
    end
 
@@ -577,22 +621,23 @@ do
    local function add_expr_expr(a, b)
       local a_count = a.term_count
       local b_count = b.term_count
-      local ret = ffi_gc(ffi_new(Expression, a_count + b_count), ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
+      local ret = ffi_gc(ffi_new(Expression, a_count + b_count), ljkiwi.kiwi_expression_destroy) --[[@as kiwi.Expression]]
 
       for i = 0, a_count - 1 do
          local dt = ret.terms_[i] --[[@as kiwi.Term]]
          local st = a.terms_[i] --[[@as kiwi.Term]]
-         dt.var = ckiwi.kiwi_var_clone(st.var)
+         dt.var = st.var
          dt.coefficient = st.coefficient
       end
       for i = 0, b_count - 1 do
          local dt = ret.terms_[a_count + i] --[[@as kiwi.Term]]
          local st = b.terms_[i] --[[@as kiwi.Term]]
-         dt.var = ckiwi.kiwi_var_clone(st.var)
+         dt.var = st.var
          dt.coefficient = st.coefficient
       end
       ret.constant = a.constant + b.constant
       ret.term_count = a_count + b_count
+      ljkiwi.kiwi_expression_retain(ret)
       return ret
    end
 
@@ -600,16 +645,17 @@ do
    ---@param constant number
    ---@nodiscard
    local function new_expr_constant(expr, constant)
-      local ret = ffi_gc(ffi_new(Expression, expr.term_count), ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
+      local ret = ffi_gc(ffi_new(Expression, expr.term_count), ljkiwi.kiwi_expression_destroy) --[[@as kiwi.Expression]]
 
       for i = 0, expr.term_count - 1 do
          local dt = ret.terms_[i] --[[@as kiwi.Term]]
          local st = expr.terms_[i] --[[@as kiwi.Term]]
-         dt.var = ckiwi.kiwi_var_clone(st.var)
+         dt.var = st.var
          dt.coefficient = st.coefficient
       end
       ret.constant = constant
       ret.term_count = expr.term_count
+      ljkiwi.kiwi_expression_retain(ret)
       return ret
    end
 
@@ -645,17 +691,18 @@ do
       __index = Expression_cls,
    }
 
-   function Expression_mt.__new(T, constant, ...)
+   function Expression_mt:__new(constant, ...)
       local term_count = select("#", ...)
-      local e = ffi_gc(ffi_new(T, term_count), ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
+      local e = ffi_gc(ffi_new(self, term_count), ljkiwi.kiwi_expression_destroy) --[[@as kiwi.Expression]]
       e.term_count = term_count
       e.constant = constant
       for i = 1, term_count do
          local t = select(i, ...)
          local dt = e.terms_[i - 1] --[[@as kiwi.Term]]
-         dt.var = ckiwi.kiwi_var_clone(t.var)
+         dt.var = t.var
          dt.coefficient = t.coefficient
       end
+      ljkiwi.kiwi_expression_retain(e)
       return e
    end
 
@@ -722,29 +769,29 @@ do
    local Constraint_cls = {
       --- The strength of the constraint.
       ---@type fun(self: kiwi.Constraint): number
-      strength = ckiwi.kiwi_constraint_strength,
+      strength = ljkiwi.kiwi_constraint_strength,
 
       --- The relational operator of the constraint.
       ---@type fun(self: kiwi.Constraint): kiwi.RelOp
-      op = ckiwi.kiwi_constraint_op,
+      op = ljkiwi.kiwi_constraint_op,
 
       --- Whether the constraint is violated in the current solution.
       ---@type fun(self: kiwi.Constraint): boolean
-      violated = ckiwi.kiwi_constraint_violated,
+      violated = ljkiwi.kiwi_constraint_violated,
    }
 
    --- The reduced expression defining the constraint.
    ---@return kiwi.Expression
    ---@nodiscard
    function Constraint_cls:expression()
-      local SZ = 7 -- 2**7 bytes on x64
+      local SZ = 7
       local expr = ffi_new(Expression, SZ) --[[@as kiwi.Expression]]
-      local n = ckiwi.kiwi_constraint_expression(self, expr, SZ)
+      local n = ljkiwi.kiwi_constraint_expression(self, expr, SZ)
       if n > SZ then
          expr = ffi_new(Expression, n) --[[@as kiwi.Expression]]
-         n = ckiwi.kiwi_constraint_expression(self, expr, n)
+         n = ljkiwi.kiwi_constraint_expression(self, expr, n)
       end
-      return ffi_gc(expr, ckiwi.kiwi_expression_del_vars) --[[@as kiwi.Expression]]
+      return ffi_gc(expr, ljkiwi.kiwi_expression_destroy) --[[@as kiwi.Expression]]
    end
 
    --- Add the constraint to the solver.
@@ -773,10 +820,9 @@ do
    }
 
    function Constraint_mt:__new(lhs, rhs, op, strength)
-      return ffi_gc(
-         ckiwi.kiwi_constraint_new(lhs, rhs, op or "EQ", strength or REQUIRED),
-         ckiwi.kiwi_constraint_del
-      )
+      local c = ffi_new(self)
+      ljkiwi.kiwi_constraint_construct(lhs, rhs, op or "EQ", strength or REQUIRED, c)
+      return ffi_gc(c, ljkiwi.kiwi_constraint_release)
    end
 
    local OPS = { [0] = "<=", ">=", "==" }
@@ -822,10 +868,9 @@ do
       tmpexpr.constant = constant ~= nil and constant or 0
       tmpexpr.term_count = 2
 
-      return ffi_gc(
-         ckiwi.kiwi_constraint_new(tmpexpr, nil, op or "EQ", strength or REQUIRED),
-         ckiwi.kiwi_constraint_del
-      ) --[[@as kiwi.Constraint]]
+      local c = ffi_new(Constraint)
+      ljkiwi.kiwi_constraint_construct(tmpexpr, nil, op or "EQ", strength or REQUIRED, c)
+      return ffi_gc(c, ljkiwi.kiwi_constraint_release) --[[@as kiwi.Constraint]]
    end
 
    local pair_ratio = constraints.pair_ratio
@@ -858,10 +903,10 @@ do
       local t = tmpexpr.terms_[0]
       t.var = var
       t.coefficient = 1.0
-      return ffi_gc(
-         ckiwi.kiwi_constraint_new(tmpexpr, nil, op or "EQ", strength or REQUIRED),
-         ckiwi.kiwi_constraint_del
-      ) --[[@as kiwi.Constraint]]
+
+      local c = ffi_new(Constraint)
+      ljkiwi.kiwi_constraint_construct(tmpexpr, nil, op or "EQ", strength or REQUIRED, c)
+      return ffi_gc(c, ljkiwi.kiwi_constraint_release) --[[@as kiwi.Constraint]]
    end
 end
 
@@ -947,7 +992,7 @@ do
             C.free(err)
          end
          local errdata = new_error(kind, message, solver, item)
-         local error_mask = solver and solver.error_mask_ or 0
+         local error_mask = ljkiwi.kiwi_solver_get_error_mask(solver)
          return item,
             band(error_mask, lshift(1, kind --[[@as integer]])) == 0 and error(errdata)
                or errdata
@@ -955,20 +1000,19 @@ do
       return item
    end
    ---@class kiwi.Solver: ffi.cdata*
-   ---@field package error_mask_ integer
    ---@overload fun(error_mask: (integer|(kiwi.ErrKind|integer)[] )?): kiwi.Solver
    local Solver_cls = {
       --- Test whether a constraint is in the solver.
       ---@type fun(self: kiwi.Solver, constraint: kiwi.Constraint): boolean
-      has_constraint = ckiwi.kiwi_solver_has_constraint,
+      has_constraint = ljkiwi.kiwi_solver_has_constraint,
 
       --- Test whether an edit variable has been added to the solver.
       ---@type fun(self: kiwi.Solver, var: kiwi.Var): boolean
-      has_edit_var = ckiwi.kiwi_solver_has_edit_var,
+      has_edit_var = ljkiwi.kiwi_solver_has_edit_var,
 
       --- Update the values of the external solver variables.
       ---@type fun(self: kiwi.Solver)
-      update_vars = ckiwi.kiwi_solver_update_vars,
+      update_vars = ljkiwi.kiwi_solver_update_vars,
 
       --- Reset the solver to the empty starting conditions.
       ---
@@ -978,11 +1022,11 @@ do
       --- when the entire system must change, since it can avoid unecessary
       --- heap (de)allocations.
       ---@type fun(self: kiwi.Solver)
-      reset = ckiwi.kiwi_solver_reset,
+      reset = ljkiwi.kiwi_solver_reset,
 
       --- Dump a representation of the solver to stdout.
       ---@type fun(self: kiwi.Solver)
-      dump = ckiwi.kiwi_solver_dump,
+      dump = ljkiwi.kiwi_solver_dump,
    }
 
    --- Sets the error mask for the solver.
@@ -992,7 +1036,7 @@ do
       if type(mask) == "table" then
          mask = kiwi.error_mask(mask, invert)
       end
-      self.error_mask_ = mask
+      ljkiwi.kiwi_solver_set_error_mask(self, mask)
    end
 
    ---@generic T
@@ -1017,7 +1061,7 @@ do
    ---@param constraint kiwi.Constraint
    ---@return kiwi.Constraint constraint, kiwi.Error?
    function Solver_cls:add_constraint(constraint)
-      return try_solver(ckiwi.kiwi_solver_add_constraint, self, constraint)
+      return try_solver(ljkiwi.kiwi_solver_add_constraint, self, constraint)
    end
 
    --- Add constraints to the solver.
@@ -1027,7 +1071,7 @@ do
    ---@param constraints kiwi.Constraint[]
    ---@return kiwi.Constraint[] constraints, kiwi.Error?
    function Solver_cls:add_constraints(constraints)
-      return add_remove_items(self, constraints, ckiwi.kiwi_solver_add_constraint)
+      return add_remove_items(self, constraints, ljkiwi.kiwi_solver_add_constraint)
    end
 
    --- Remove a constraint from the solver.
@@ -1036,7 +1080,7 @@ do
    ---@param constraint kiwi.Constraint
    ---@return kiwi.Constraint constraint, kiwi.Error?
    function Solver_cls:remove_constraint(constraint)
-      return try_solver(ckiwi.kiwi_solver_remove_constraint, self, constraint)
+      return try_solver(ljkiwi.kiwi_solver_remove_constraint, self, constraint)
    end
 
    --- Remove constraints from the solver.
@@ -1045,7 +1089,7 @@ do
    ---@param constraints kiwi.Constraint[]
    ---@return kiwi.Constraint[] constraints, kiwi.Error?
    function Solver_cls:remove_constraints(constraints)
-      return add_remove_items(self, constraints, ckiwi.kiwi_solver_remove_constraint)
+      return add_remove_items(self, constraints, ljkiwi.kiwi_solver_remove_constraint)
    end
 
    --- Add an edit variables to the solver.
@@ -1059,7 +1103,7 @@ do
    ---@param strength number the strength of the edit variable (must be less than `Strength.REQUIRED`)
    ---@return kiwi.Var var, kiwi.Error?
    function Solver_cls:add_edit_var(var, strength)
-      return try_solver(ckiwi.kiwi_solver_add_edit_var, self, var, strength)
+      return try_solver(ljkiwi.kiwi_solver_add_edit_var, self, var, strength)
    end
 
    --- Add edit variables to the solver.
@@ -1073,7 +1117,7 @@ do
    ---@param strength number the strength of the edit variables (must be less than `Strength.REQUIRED`)
    ---@return kiwi.Var[] vars, kiwi.Error?
    function Solver_cls:add_edit_vars(vars, strength)
-      return add_remove_items(self, vars, ckiwi.kiwi_solver_add_edit_var, strength)
+      return add_remove_items(self, vars, ljkiwi.kiwi_solver_add_edit_var, strength)
    end
 
    --- Remove an edit variable from the solver.
@@ -1082,7 +1126,7 @@ do
    ---@param var kiwi.Var the edit variable to remove
    ---@return kiwi.Var var, kiwi.Error?
    function Solver_cls:remove_edit_var(var)
-      return try_solver(ckiwi.kiwi_solver_remove_edit_var, self, var)
+      return try_solver(ljkiwi.kiwi_solver_remove_edit_var, self, var)
    end
 
    --- Removes edit variables from the solver.
@@ -1091,7 +1135,7 @@ do
    ---@param vars kiwi.Var[] the edit variables to remove
    ---@return kiwi.Var[] vars, kiwi.Error?
    function Solver_cls:remove_edit_vars(vars)
-      return add_remove_items(self, vars, ckiwi.kiwi_solver_remove_edit_var)
+      return add_remove_items(self, vars, ljkiwi.kiwi_solver_remove_edit_var)
    end
 
    --- Suggest a value for the given edit variable.
@@ -1104,7 +1148,7 @@ do
    ---@param value number the suggested value
    ---@return kiwi.Var var, kiwi.Error?
    function Solver_cls:suggest_value(var, value)
-      return try_solver(ckiwi.kiwi_solver_suggest_value, self, var, value)
+      return try_solver(ljkiwi.kiwi_solver_suggest_value, self, var, value)
    end
 
    --- Suggest values for the given edit variables.
@@ -1116,7 +1160,7 @@ do
    ---@return kiwi.Var[] vars, number[] values, kiwi.Error?
    function Solver_cls:suggest_values(vars, values)
       for i, var in ipairs(vars) do
-         local _, err = try_solver(ckiwi.kiwi_solver_suggest_value, self, var, values[i])
+         local _, err = try_solver(ljkiwi.kiwi_solver_suggest_value, self, var, values[i])
          if err ~= nil then
             return vars, values, err
          end
@@ -1128,7 +1172,7 @@ do
    ---@return string
    ---@nodiscard
    function Solver_cls:dumps()
-      local cs = ckiwi.kiwi_solver_dumps(self)
+      local cs = ljkiwi.kiwi_solver_dumps(self)
       local s = ffi_string(cs)
       C.free(cs)
       return s
@@ -1138,17 +1182,23 @@ do
       __index = Solver_cls,
    }
 
+   local Solver = ffi.typeof("struct KiwiSolver") --[[@as kiwi.Solver]]
+   kiwi.Solver = Solver
+
    function Solver_mt:__new(error_mask)
       if type(error_mask) == "table" then
          error_mask = kiwi.error_mask(error_mask)
       end
-      return ffi_gc(ckiwi.kiwi_solver_new(error_mask or 0), ckiwi.kiwi_solver_del)
+
+      local s = ffi_new(Solver)
+      ljkiwi.kiwi_solver_construct(error_mask or 0, s)
+      return ffi_gc(s, ljkiwi.kiwi_solver_destroy) --[[@as kiwi.Constraint]]
    end
 
-   kiwi.Solver = ffi.metatype("struct KiwiSolver", Solver_mt) --[[@as kiwi.Solver]]
+   kiwi.Solver = ffi.metatype(Solver, Solver_mt) --[[@as kiwi.Solver]]
 
    function kiwi.is_solver(s)
-      return ffi_istype(kiwi.Solver, s)
+      return ffi_istype(Solver, s)
    end
 end
 

ljkiwi.def

@@ -0,0 +1,37 @@
+EXPORTS
+luaopen_ljkiwi
+
+kiwi_ti_KiwiVar
+kiwi_ti_KiwiConstraint
+kiwi_ti_KiwiSolver
+
+kiwi_constraint_construct
+kiwi_constraint_expression
+kiwi_constraint_op
+kiwi_constraint_release
+kiwi_constraint_retain
+kiwi_constraint_strength
+kiwi_constraint_violated
+kiwi_expression_destroy
+kiwi_solver_add_constraint
+kiwi_solver_add_edit_var
+kiwi_solver_construct
+kiwi_solver_destroy
+kiwi_solver_dump
+kiwi_solver_dumps
+kiwi_solver_has_constraint
+kiwi_solver_has_edit_var
+kiwi_solver_remove_constraint
+kiwi_solver_remove_edit_var
+kiwi_solver_reset
+kiwi_solver_suggest_value
+kiwi_solver_update_vars
+kiwi_var_construct
+kiwi_var_destroy
+kiwi_var_eq
+kiwi_var_name
+kiwi_var_release
+kiwi_var_retain
+kiwi_var_set_name
+kiwi_var_set_value
+kiwi_var_value

ljkiwi.hpp

@@ -0,0 +1 @@
+#include <kiwi/kiwi.h>

luakiwi/.clang-format

@@ -1,88 +0,0 @@
-AccessModifierOffset: -2
-AlignAfterOpenBracket: BlockIndent    # New in v14. For earlier clang-format versions, use AlwaysBreak instead.
-AlignConsecutiveMacros: false
-AlignConsecutiveAssignments: false
-AlignConsecutiveDeclarations: false
-AlignEscapedNewlines: DontAlign
-AlignOperands: false
-AlignTrailingComments: false
-AllowAllArgumentsOnNextLine: false
-AllowAllConstructorInitializersOnNextLine: false
-AllowAllParametersOfDeclarationOnNextLine: false
-AllowShortBlocksOnASingleLine: Empty
-AllowShortCaseLabelsOnASingleLine: false
-AllowShortFunctionsOnASingleLine: Empty
-AllowShortIfStatementsOnASingleLine: Never
-AllowShortLambdasOnASingleLine: All
-AllowShortLoopsOnASingleLine: false
-AlwaysBreakAfterReturnType: None
-AlwaysBreakBeforeMultilineStrings: true
-AlwaysBreakTemplateDeclarations: Yes
-BinPackArguments: false
-BinPackParameters: false
-BreakAfterAttributes: Always
-BreakBeforeBinaryOperators: NonAssignment
-BreakBeforeBraces: Attach
-BreakBeforeTernaryOperators: true
-BreakConstructorInitializers: AfterColon
-BreakInheritanceList: AfterColon
-BreakStringLiterals: false
-ColumnLimit: 98
-CompactNamespaces: false
-ConstructorInitializerAllOnOneLineOrOnePerLine: true
-ConstructorInitializerIndentWidth: 4
-ContinuationIndentWidth: 4
-Cpp11BracedListStyle: true
-DerivePointerAlignment: false
-FixNamespaceComments: true
-IncludeBlocks: Regroup
-IncludeCategories:
-  - Regex:           '^<ext/.*\.h>'
-    Priority:        2
-    SortPriority:    0
-    CaseSensitive:   false
-  - Regex:           '^<.*\.h>'
-    Priority:        1
-    SortPriority:    0
-    CaseSensitive:   false
-  - Regex:           '^<.*'
-    Priority:        2
-    SortPriority:    0
-    CaseSensitive:   false
-  - Regex:           '.*'
-    Priority:        3
-    SortPriority:    0
-    CaseSensitive:   false
-IncludeIsMainRegex: '([-_](test|unittest))?$'
-IndentCaseLabels: true
-IndentPPDirectives: BeforeHash
-IndentWidth: 3
-IndentWrappedFunctionNames: false
-KeepEmptyLinesAtTheStartOfBlocks: false
-MaxEmptyLinesToKeep: 1
-NamespaceIndentation: Inner
-PointerAlignment: Left
-ReferenceAlignment: Left              # New in v13. int &name  ==>  int& name
-ReflowComments: false
-SeparateDefinitionBlocks: Always      # New in v14.
-SortIncludes: true
-SortUsingDeclarations: true
-SpaceAfterCStyleCast: false
-SpaceAfterLogicalNot: false
-SpaceAfterTemplateKeyword: false
-SpaceBeforeAssignmentOperators: true
-SpaceBeforeCpp11BracedList: true
-SpaceBeforeCtorInitializerColon: true
-SpaceBeforeInheritanceColon: false
-SpaceBeforeParens: ControlStatements
-SpaceBeforeRangeBasedForLoopColon: true
-SpaceInEmptyParentheses: false
-SpacesBeforeTrailingComments: 2
-SpacesInAngles: false
-SpacesInCStyleCastParentheses: false
-SpacesInContainerLiterals: false
-SpacesInParentheses: false
-SpacesInSquareBrackets: false
-Standard: Cpp11
-TabWidth: 4
-UseTab: Never

luakiwi/luakiwi-int.h

@@ -4,21 +4,24 @@
 #include <kiwi/kiwi.h>
 
 #include <cstring>
+#include <new>
 
 #include "luacompat.h"
 
-#define ARR_COUNT(x) ((int)(sizeof(x) / sizeof((x)[0])))
-
-#if defined(__GNUC__) && !defined(LKIWI_NO_BUILTIN)
-   #define l_likely(x) (__builtin_expect(((x) != 0), 1))
-   #define l_unlikely(x) (__builtin_expect(((x) != 0), 0))
+#if defined(__GNUC__) && !defined(LJKIWI_NO_BUILTIN)
+   #define lk_likely(x) (__builtin_expect(((x) != 0), 1))
+   #define lk_unlikely(x) (__builtin_expect(((x) != 0), 0))
 #else
-   #define l_likely(x) (x)
-   #define l_unlikely(x) (x)
+   #define lk_likely(x) (x)
+   #define lk_unlikely(x) (x)
 #endif
 
+namespace {
+
+using namespace kiwi;
+
 // Lua 5.1 compatibility for missing lua_arith.
-static void compat_arith_unm(lua_State* L) {
+inline void compat_arith_unm(lua_State* L) {
 #if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM == 501
    lua_Number n = lua_tonumber(L, -1);
    if (n != 0 || lua_isnumber(L, -1)) {
@@ -35,14 +38,13 @@ static void compat_arith_unm(lua_State* L) {
 }
 
 // This version supports placeholders.
-static void setfuncs(lua_State* L, const luaL_Reg* l, int nup) {
+inline void setfuncs(lua_State* L, const luaL_Reg* l, int nup) {
    luaL_checkstack(L, nup, "too many upvalues");
    for (; l->name != NULL; l++) { /* fill the table with given functions */
       if (l->func == NULL) /* place holder? */
          lua_pushboolean(L, 0);
       else {
-         int i;
-         for (i = 0; i < nup; i++) /* copy upvalues to the top */
+         for (int i = 0; i < nup; i++) /* copy upvalues to the top */
             lua_pushvalue(L, -nup);
          lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */
       }
@@ -51,11 +53,15 @@ static void setfuncs(lua_State* L, const luaL_Reg* l, int nup) {
    lua_pop(L, nup); /* remove upvalues */
 }
 
-#define newlib(L, l) (lua_newtable((L)), setfuncs((L), (l), 0))
+template<typename T, std::size_t N>
+constexpr int array_count(T (&)[N]) {
+   return static_cast<int>(N);
+}
 
-namespace {
-
-using namespace kiwi;
+inline void newlib(lua_State* L, const luaL_Reg* l) {
+   lua_newtable(L);
+   setfuncs(L, l, 0);
+}
 
 enum KiwiErrKind {
    KiwiErrNone,
@@ -80,15 +86,32 @@ struct KiwiExpression {
    double constant;
    int term_count;
    Constraint* owner;
+
+#if !defined(_MSC_VER) || _MSC_VER >= 1900
+   KiwiTerm terms[];
+
+   static constexpr std::size_t sz(int count) {
+      return sizeof(KiwiExpression) + sizeof(KiwiTerm) * (count > 0 ? count : 0);
+   }
+#else
    KiwiTerm terms[1];
+
+   static constexpr std::size_t sz(int count) {
+      return sizeof(KiwiExpression) + sizeof(KiwiTerm) * (count > 1 ? count - 1 : 0);
+   }
+#endif
+
+   KiwiExpression() = delete;
+   KiwiExpression(const KiwiExpression&) = delete;
+   KiwiExpression& operator=(const KiwiExpression&) = delete;
+   ~KiwiExpression() = delete;
 };
 
-// This structure was initially designed for LuaJIT FFI. It works OK for C++
-// though it certainly isn't idiomatic.
+// This mechanism was initially designed for LuaJIT FFI.
 struct KiwiErr {
    enum KiwiErrKind kind;
    const char* message;
-   bool must_free;
+   bool must_delete;
 };
 
 struct KiwiSolver {
@@ -96,60 +119,59 @@ struct KiwiSolver {
    Solver solver;
 };
 
-const KiwiErr* new_error(const KiwiErr* base, const std::exception& ex) {
+inline const KiwiErr* new_error(const KiwiErr* base, const std::exception& ex) {
    if (!std::strcmp(ex.what(), base->message))
       return base;
 
    const auto msg_n = std::strlen(ex.what()) + 1;
 
-   auto* mem = static_cast<char*>(std::malloc(sizeof(KiwiErr) + msg_n));
+   auto* mem = static_cast<char*>(::operator new(sizeof(KiwiErr) + msg_n, std::nothrow));
    if (!mem) {
       return base;
    }
-
-   const auto* err = new (mem) KiwiErr {base->kind, mem + sizeof(KiwiErr), true};
-   std::memcpy(const_cast<char*>(err->message), ex.what(), msg_n);
-   return err;
+   auto* msg = mem + sizeof(KiwiErr);
+   std::memcpy(msg, ex.what(), msg_n);
+   return new (mem) KiwiErr {base->kind, msg, true};
 }
 
-const constexpr KiwiErr kKiwiErrUnhandledCxxException {
-    KiwiErrUnknown,
-    "An unhandled C++ exception occurred."};
-
 template<typename F>
 inline const KiwiErr* wrap_err(F&& f) {
+   static const constexpr KiwiErr kKiwiErrUnhandledCxxException {
+       KiwiErrUnknown,
+       "An unhandled C++ exception occurred."};
+
    try {
       f();
-   } catch (const UnsatisfiableConstraint& ex) {
+   } catch (const UnsatisfiableConstraint&) {
       static const constexpr KiwiErr err {
           KiwiErrUnsatisfiableConstraint,
           "The constraint cannot be satisfied."};
       return &err;
-   } catch (const UnknownConstraint& ex) {
+   } catch (const UnknownConstraint&) {
       static const constexpr KiwiErr err {
           KiwiErrUnknownConstraint,
           "The constraint has not been added to the solver."};
       return &err;
 
-   } catch (const DuplicateConstraint& ex) {
+   } catch (const DuplicateConstraint&) {
       static const constexpr KiwiErr err {
           KiwiErrDuplicateConstraint,
           "The constraint has already been added to the solver."};
       return &err;
 
-   } catch (const UnknownEditVariable& ex) {
+   } catch (const UnknownEditVariable&) {
       static const constexpr KiwiErr err {
           KiwiErrUnknownEditVariable,
           "The edit variable has not been added to the solver."};
       return &err;
 
-   } catch (const DuplicateEditVariable& ex) {
+   } catch (const DuplicateEditVariable&) {
       static const constexpr KiwiErr err {
           KiwiErrDuplicateEditVariable,
           "The edit variable has already been added to the solver."};
       return &err;
 
-   } catch (const BadRequiredStrength& ex) {
+   } catch (const BadRequiredStrength&) {
       static const constexpr KiwiErr err {
           KiwiErrBadRequiredStrength,
           "A required strength cannot be used in this context."};
@@ -193,12 +215,12 @@ inline Constraint* kiwi_constraint_retain(Constraint* c) {
    return c;
 }
 
-inline void kiwi_constraint_new(
+inline Constraint* kiwi_constraint_new(
     const KiwiExpression* lhs,
     const KiwiExpression* rhs,
     RelationalOperator op,
     double strength,
-    Constraint* mem
+    void* mem
 ) {
    if (strength < 0.0) {
       strength = kiwi::strength::required;
@@ -217,7 +239,7 @@ inline void kiwi_constraint_new(
          terms.emplace_back(*t->var, -t->coefficient);
       }
    }
-   new (mem) Constraint(
+   return new (mem) Constraint(
        Expression(std::move(terms), (lhs ? lhs->constant : 0.0) - (rhs ? rhs->constant : 0.0)),
        static_cast<RelationalOperator>(op),
        strength

t.lua

@@ -8,14 +8,16 @@ do
    local v3 = kiwi.Var("v3")
    local v4 = kiwi.Var("v4")
    local v5 = kiwi.Var("v5")
-   local c = (3 * v1 + 4 * v2 + 6 * v3):eq(0)
+   local c1 = (3 * v1 + 4 * v2 + 6 * v3):eq(0)
+   local c2 = (6 * v4 + 4 * v5 + 2 * v1 + 1.4 * v1 / 0.3):le(1000)
 
-   local e = c:expression()
-   print(e)
+   local e = c1:expression()
+   local s = kiwi.Solver()
+
+   s:add_constraints({ c1, c2, c1 })
+   print(s:dumps())
 end
 
-collectgarbage("collect")
-collectgarbage("collect")
 -- c = (3 * v1 + 4 * v2 + 6 * v3):eq(0)
 
 -- local t = c:expression():terms()