c ++ initializer_list和shared_ptr行为 [英] c++ initializer_list and shared_ptr behavior
问题描述
我正在测试vs2013 c ++ initializer_list。
I'm testing vs2013 c++ initializer_list.
下面的代码可以编译。
但是当我运行exe时崩溃。
The code below can be compiled. But crashes when i run exe.
#include <memory>
#include <iostream>
class Base {};
class Derived : public Base {};
void DoSomething(std::initializer_list<std::shared_ptr<Base> > list)
{
}
int main()
{
auto ip = std::make_shared<Derived>();
std::cout << "use_count=" << ip.use_count() << std::endl;
DoSomething({ip, std::make_shared<Derived>()}); // ng
// DoSomething({ip, std::make_shared<Base>()}); // ok
// DoSomething({std::make_shared<Derived>(), ip}); // ok
std::cout << "use_count=" << ip.use_count() << std::endl;
}
编译。
C:\...>cl.exe /EHsc test.cpp
Microsoft(R) C/C++ Optimizing Compiler Version 18.00.21005.1 for x86
Copyright (C) Microsoft Corporation. All rights reserved.
test.cpp
Microsoft (R) Incremental Linker Version 12.00.21005.1
Copyright (C) Microsoft Corporation. All rights reserved.
/out:test.exe
test.obj
C:\...>
我期望的输出像这样。
g ++ 4.8.2就像这样。
I expected the output like this. g++4.8.2 works like this.
c:\...>test.exe
use_count=1
use_count=1
但是, / p>
However, looks like this.
c:\...>test.exe
use_count=1
use_count=0 // or some random value like 3719232 and displayed crash dialog.
然后,修改上面的代码中的一行,这很好。
And, Modifying one line of the code above, This works good.
DoSomething({std::make_shared<Derived>(), ip});
这是vs2013 initializer_list的错误还是正常的行为?
Is this a bug or normal behavior of vs2013 initializer_list ?
推荐答案
这是vs2013 initializer_list的错误或正常行为吗?
Is this a bug or normal behavior of vs2013 initializer_list?
是的。 VS2013的 std :: initializer_list
实现是错误的;请参阅类似的问题为什么第一个元素被销毁?和在initializer_list vs 2013中双击删除。
Yes to both. VS2013's std::initializer_list
implementation is buggy; see similar questions Why first element is destroyed? and Double delete in initializer_list vs 2013.
有人在2013年11月向Microsoft报告了其中一个问题: http://connect.microsoft.com/VisualStudio/feedback/details/807419/initializer-lists -leaking-memory
Someone reported one of those issues to Microsoft in November 2013: http://connect.microsoft.com/VisualStudio/feedback/details/807419/initializer-lists-leaking-memory
这在Spring更新中已修复:
在Visual Studio 2013 Update 2中修复的错误
This is now fixed in the Spring Update: Bugs Fixed in Visual Studio 2013 Update 2
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