Open
Description
Describe the bug
Using iterators to iterate std::vector in a loop within consteval function leads to an error "failure was caused by a read of a variable outside its lifetime"
Command-line test case
C:\Temp>type repro.cpp
#include <vector>
consteval void func()
{
std::vector<int> v;
for (auto it = v.begin(); it != v.end(); ++it) {}
}
int main()
{
func();
}
C:\Temp>cl /EHsc /W4 /WX /MDd /std:c++latest .\repro.cpp
Microsoft (R) C/C++ Optimizing Compiler Version 19.42.34433 for x64
Copyright (C) Microsoft Corporation. All rights reserved.
/std:c++latest is provided as a preview of language features from the latest C++
working draft, and we're eager to hear about bugs and suggestions for improvements.
However, note that these features are provided as-is without support, and subject
to changes or removal as the working draft evolves. See
https://go.microsoft.com/fwlink/?linkid=2045807 for details.
repro.cpp
.\repro.cpp(11): error C7595: 'func': call to immediate function is not a constant expression
C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.42.34433\include\xmemory(1352): note: failure was caused by a read of a variable outside its lifetime
C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.42.34433\include\xmemory(1352): note: see usage of 'it'
.\repro.cpp(11): note: the call stack of the evaluation (the oldest call first) is
.\repro.cpp(11): note: while evaluating function 'void func(void)'
.\repro.cpp(5): note: while evaluating function 'std::vector<int,std::allocator<int>>::~vector(void) noexcept'
C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.42.34433\include\vector(761): note: while evaluating function 'void std::vector<int,std::allocator<int>>::_Tidy(void) noexcept'
C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.42.34433\include\vector(2045): note: while evaluating function 'void std::_Container_base12::_Orphan_all(void) noexcept'
C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.42.34433\include\xmemory(1360): note: while evaluating function 'void std::_Container_base12::_Orphan_all_unlocked_v3(void) noexcept'
Expected behavior
No error with /ITERATOR_DEBUG_LEVEL=2
STL version
Microsoft Visual Studio Community 2022 (64-bit) - Current
Version 17.12.0
Additional context
Example on Godbolt
Could be worked around by compiling in release mode or using _ITERATOR_DEBUG_LEVEL=1(or 0)
Hard to tell if the issue is in compiler or in iterator debug level machinery