https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81202
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |rejects-valid
Status|UNCONFIRMED |NEW
Last reconfirmed| |2019-12-03
Blocks| |67491
Ever confirmed|0 |1
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Your spacebar seems to be broken, and your testcase is incomplete ("tple"?!)
Fixed:
template<class T, class AT = void>
constexpr bool IsPtrC = true;
template<class T, class AT = void> concept bool IsPtrC2 = IsPtrC<T, AT>;
template<bool B> using TEST = int;
TEST<IsPtrC<int>> i; // OK
TEST<IsPtrC2<int>> j; // error: parse error in template argument list
TEST<IsPtrC2<int, void>> k; // OK
TEST<(IsPtrC2<int>)> l; // OK
This is still rejected by current versions of GCC with -std=gnu++17 -fconcepts.
With GCC 8 and 9:
81202.cc:9:1: error: parse error in template argument list
9 | TEST<IsPtrC2<int>> j; // error: parse error in template argument
list
| ^~~~~~~~~~~~~~~~~~~~
81202.cc:9:1: error: declaration does not declare anything [-fpermissive]
And with trunk:
81202.cc:9:17: error: type/value mismatch at argument 1 in template parameter
list for 'template<bool B> using TEST = int'
9 | TEST<IsPtrC2<int>> j; // error: parse error in template argument
list
| ^~
81202.cc:9:17: note: expected a constant of type 'bool', got 'auto [requires
IsPtrC2<<placeholder>, int>]'
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67491
[Bug 67491] [meta-bug] concepts issues
