Mikhail Maltsev 2b20304def [libcxx] Avoid spurious construction of valarray elements
Summary:
Currently libc++ implements some operations on valarray by using the
resize method. This method has a parameter with a default value.
Because of this, valarray may spuriously construct and destruct
objects of valarray's element type.
    
This patch fixes this issue and adds corresponding test cases.


Reviewers: EricWF, mclow.lists

Reviewed By: mclow.lists

Subscribers: rogfer01, cfe-commits

Differential Revision: https://reviews.llvm.org/D41992

llvm-svn: 324596
2018-02-08 11:33:48 +00:00

50 lines
1007 B
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.
//
//===----------------------------------------------------------------------===//
// <valarray>
// template<class T> class valarray;
// valarray();
#include <valarray>
#include <cassert>
struct S {
S() { ctor_called = true; }
static bool ctor_called;
};
bool S::ctor_called = false;
int main()
{
{
std::valarray<int> v;
assert(v.size() == 0);
}
{
std::valarray<float> v;
assert(v.size() == 0);
}
{
std::valarray<double> v;
assert(v.size() == 0);
}
{
std::valarray<std::valarray<double> > v;
assert(v.size() == 0);
}
{
std::valarray<S> v;
assert(v.size() == 0);
assert(!S::ctor_called);
}
}