https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84421
Bug ID: 84421
Summary: [8 Regression] Lambda parameter is no longer a core
constant expressions
Product: gcc
Version: 8.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: benni.buch at gmail dot com
Target Milestone: ---
struct A{
constexpr operator bool()const{ return true; }
};
int main(){
auto f = [](auto v){ if constexpr(v){} };
A a;
f(a);
}
$ g++ -std=c++17 main.cpp
main.cpp: In lambda function:
main.cpp:6:40: error: 'v' is not a constant expression
auto f = [](auto v){ if constexpr(v){} };
^
$ g++ --version
g++ (GCC) 8.0.1 20180216 (experimental)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Known to work with GCC-7:
$ g++-7 --version
g++ (GCC) 7.3.1 20180216
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
