//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// <functional>
// REQUIRES: c++11 || c++14

// class function<R(ArgTypes...)>

// template<class F, class A> function(allocator_arg_t, const A&, F);

#include <functional>
#include <cassert>

#include "test_macros.h"
#include "min_allocator.h"
#include "test_allocator.h"
#include "count_new.h"
#include "../function_types.h"

#if TEST_STD_VER >= 11
struct RValueCallable {
    template <class ...Args>
    void operator()(Args&&...) && {}
};
struct LValueCallable {
    template <class ...Args>
    void operator()(Args&&...) & {}
};
#endif

template <class T>
struct non_default_test_allocator : test_allocator<T> {
  non_default_test_allocator() = delete;
  using test_allocator<T>::test_allocator;
};

test_allocator_statistics alloc_stats;

class DummyClass {};

template <class FuncType, class AllocType>
void test_FunctionObject(AllocType& alloc)
{
    assert(globalMemCounter.checkOutstandingNewEq(0));
    {
    FunctionObject target;
    assert(FunctionObject::count == 1);
    assert(globalMemCounter.checkOutstandingNewEq(0));
    std::function<FuncType> f2(std::allocator_arg, alloc, target);
    assert(FunctionObject::count == 2);
    assert(globalMemCounter.checkOutstandingNewEq(1));
    assert(f2.template target<FunctionObject>());
    assert(f2.template target<FuncType>() == 0);
    assert(f2.template target<FuncType*>() == 0);
    }
    assert(FunctionObject::count == 0);
    assert(globalMemCounter.checkOutstandingNewEq(0));
}


template <class FuncType, class AllocType>
void test_FreeFunction(AllocType& alloc)
{
    assert(globalMemCounter.checkOutstandingNewEq(0));
    {
    FuncType* target = &FreeFunction;
    assert(globalMemCounter.checkOutstandingNewEq(0));
    std::function<FuncType> f2(std::allocator_arg, alloc, target);
    // The allocator may not fit in the small object buffer, if we allocated
    // check it was done via the allocator.
    assert(globalMemCounter.checkOutstandingNewEq(alloc_stats.alloc_count));
    assert(f2.template target<FuncType*>());
    assert(*f2.template target<FuncType*>() == target);
    assert(f2.template target<FuncType>() == 0);
    assert(f2.template target<DummyClass>() == 0);
    }
    assert(globalMemCounter.checkOutstandingNewEq(0));
}

template <class TargetType, class FuncType, class AllocType>
void test_MemFunClass(AllocType& alloc)
{
    assert(globalMemCounter.checkOutstandingNewEq(0));
    {
    TargetType target = &MemFunClass::foo;
    assert(globalMemCounter.checkOutstandingNewEq(0));
    std::function<FuncType> f2(std::allocator_arg, alloc, target);
    assert(globalMemCounter.checkOutstandingNewEq(alloc_stats.alloc_count));
    assert(f2.template target<TargetType>());
    assert(*f2.template target<TargetType>() == target);
    assert(f2.template target<FuncType*>() == 0);
    }
    assert(globalMemCounter.checkOutstandingNewEq(0));
}

template <class Alloc>
void test_for_alloc(Alloc& alloc) {
    test_FunctionObject<int()>(alloc);
    test_FunctionObject<int(int)>(alloc);
    test_FunctionObject<int(int, int)>(alloc);
    test_FunctionObject<int(int, int, int)>(alloc);

    test_FreeFunction<int()>(alloc);
    test_FreeFunction<int(int)>(alloc);
    test_FreeFunction<int(int, int)>(alloc);
    test_FreeFunction<int(int, int, int)>(alloc);

    test_MemFunClass<int(MemFunClass::*)() const, int(MemFunClass&)>(alloc);
    test_MemFunClass<int(MemFunClass::*)(int) const, int(MemFunClass&, int)>(alloc);
    test_MemFunClass<int(MemFunClass::*)(int, int) const, int(MemFunClass&, int, int)>(alloc);
}

int main(int, char**) {
  globalMemCounter.reset();
  {
    bare_allocator<DummyClass> bare_alloc;
    test_for_alloc(bare_alloc);
  }
    {
        non_default_test_allocator<DummyClass> non_default_alloc(42, &alloc_stats);
        test_for_alloc(non_default_alloc);
    }
#if TEST_STD_VER >= 11
    {
        using Fn = std::function<void(int, int, int)>;
        static_assert(std::is_constructible<Fn, std::allocator_arg_t, std::allocator<int>, LValueCallable&>::value, "");
        static_assert(std::is_constructible<Fn, std::allocator_arg_t, std::allocator<int>, LValueCallable>::value, "");
        static_assert(!std::is_constructible<Fn, std::allocator_arg_t, std::allocator<int>, RValueCallable&>::value, "");
        static_assert(!std::is_constructible<Fn, std::allocator_arg_t, std::allocator<int>, RValueCallable>::value, "");
    }
#endif


  return 0;
}