Eric Fiselier c3231d213a [libcxx] Fix PR 22468 - std::function<void()> does not accept non-void-returning functions
Summary:
The bug can be found here: http://llvm.org/bugs/show_bug.cgi?id=22468

`__invoke_void_return_wrapper` is needed to properly handle calling a function that returns a value but where the std::function return type is void. Without this '-Wsystem-headers' will cause `function::operator()(...)` to not compile. 

Reviewers: eugenis, K-ballo, mclow.lists

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D7444

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@228705 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-10 16:48:45 +00:00

91 lines
2.0 KiB
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <functional>
// class function<R(ArgTypes...)>
// function(nullptr_t);
#include <functional>
#include <cassert>
#include "count_new.hpp"
class A
{
int data_[10];
public:
static int count;
A()
{
++count;
for (int i = 0; i < 10; ++i)
data_[i] = i;
}
A(const A&) {++count;}
~A() {--count;}
int operator()(int i) const
{
for (int j = 0; j < 10; ++j)
i += data_[j];
return i;
}
int foo(int) const {return 1;}
};
int A::count = 0;
int g(int) {return 0;}
int main()
{
assert(globalMemCounter.checkOutstandingNewEq(0));
{
std::function<int(int)> f = A();
assert(A::count == 1);
assert(globalMemCounter.checkOutstandingNewEq(1));
assert(f.target<A>());
assert(f.target<int(*)(int)>() == 0);
}
assert(A::count == 0);
assert(globalMemCounter.checkOutstandingNewEq(0));
{
std::function<int(int)> f = g;
assert(globalMemCounter.checkOutstandingNewEq(0));
assert(f.target<int(*)(int)>());
assert(f.target<A>() == 0);
}
assert(globalMemCounter.checkOutstandingNewEq(0));
{
std::function<int(int)> f = (int (*)(int))0;
assert(!f);
assert(globalMemCounter.checkOutstandingNewEq(0));
assert(f.target<int(*)(int)>() == 0);
assert(f.target<A>() == 0);
}
{
std::function<int(const A*, int)> f = &A::foo;
assert(f);
assert(globalMemCounter.checkOutstandingNewEq(0));
assert(f.target<int (A::*)(int) const>() != 0);
}
{
std::function<void(int)> f(&g);
assert(f);
assert(f.target<int(*)(int)>() != 0);
f(1);
}
}