https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90775
Bug ID: 90775
Summary: A inconsistent compilation result
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: zhonghao at pku dot org.cn
Target Milestone: ---
My g++ is 10.0.0, and my code is as follows:
#include <iterator>
#include <type_traits>
struct S {};
int begin(S);
template<class T> std::true_type has_cbegin(decltype(std::cbegin(T{})));
template<class T> std::false_type has_cbegin(...);
static_assert(!decltype(has_cbegin<S>(0))::value);
When compiling with -c -std=c++14, it accepts the code. However, when compiling
with -c -std=c++11 or -c -std=c++0x
/home/haozhong/project/approach/compilerpara/llvm/tmp/llvm_28927/code0.c.cpp:5:59:error:‘cbegin’
is not a member of ‘std’; did you mean ‘begin’?
5 | template<class T> std::true_type
has_cbegin(decltype(std::cbegin(T{})));
| ^~~~~~
| begin
/home/haozhong/project/approach/compilerpara/llvm/tmp/llvm_28927/code0.c.cpp:5:59:
error:‘cbegin’ is not a member of ‘std’; did you mean ‘begin’?
5 | template<class T> std::true_type
has_cbegin(decltype(std::cbegin(T{})));
| ^~~~~~
| begin
/home/haozhong/project/approach/compilerpara/llvm/tmp/llvm_28927/code0.c.cpp:7:15:
error: static assertion failed
7 | static_assert(!decltype(has_cbegin<S>(0))::value);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Something wrong with -std=c++14?
