https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107188
Bug ID: 107188
Summary: using concept type-constraint declared in nested
namespace causes incorrect compilation error
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: Mark_B53 at yahoo dot com
Target Milestone: ---
#include <concepts>
#include <ranges>
#include <vector>
namespace ns1 {
template <typename T, typename V>
concept RangeV = std::ranges::range<T> &&
std::same_as<std::ranges::range_value_t<T>, V>;
}
namespace ns2 {
ns1::RangeV<int> auto fn() { return std::vector<int>{}; } // compiles
struct X {
ns1::RangeV<int> auto fn() { return std::vector<int>{}; } // fails to
compile (bug!)
};
using ns1::RangeV;
struct Y {
RangeV<int> auto fn() { return std::vector<int>{}; } // compiles
};
}
-----
<source>:11:10: error: wrong number of template arguments (1, should be 2)
11 | ns1::RangeV<int> auto fn() { return std::vector<int>{}; } // fails
to compile (bug!)
| ^~~~~~~~~~~
<source>:6:9: note: provided for 'template<class T, class V> concept
ns1::RangeV'
6 | concept RangeV = std::ranges::range<T> &&
std::same_as<std::ranges::range_value_t<T>, V>;
-----
g++ a.cpp -std=c++20
Using built-in specs.
COLLECT_GCC=/opt/compiler-explorer/gcc-snapshot/bin/g++
Target: x86_64-linux-gnu
Configured with: ../gcc-trunk-20221008/configure
--prefix=/opt/compiler-explorer/gcc-build/staging --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu --disable-bootstrap
--enable-multiarch --with-abi=m64 --with-multilib-list=m32,m64,mx32
--enable-multilib --enable-clocale=gnu
--enable-languages=c,c++,fortran,ada,objc,obj-c++,d --enable-ld=yes
--enable-gold=yes --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--enable-linker-build-id --enable-lto --enable-plugins --enable-threads=posix
--with-pkgversion=Compiler-Explorer-Build-gcc-895dd027d5dda51a95d242aec8a49a6dfa5db58d-binutils-2.38
--enable-libstdcxx-backtrace=yes
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 13.0.0 20221007 (experimental)
(Compiler-Explorer-Build-gcc-895dd027d5dda51a95d242aec8a49a6dfa5db58d-binutils-2.38)
COLLECT_GCC_OPTIONS='-fdiagnostics-color=always' '-g' '-o' '/app/output.s'
'-masm=intel' '-S' '-v' '-std=c++20' '-isystem'
'/opt/compiler-explorer/libs/boost_1_80_0' '-shared-libgcc' '-mtune=generic'
'-march=x86-64' '-dumpdir' '/app/'
/opt/compiler-explorer/gcc-trunk-20221008/bin/../libexec/gcc/x86_64-linux-gnu/13.0.0/cc1plus
-quiet -v -imultiarch x86_64-linux-gnu -iprefix
/opt/compiler-explorer/gcc-trunk-20221008/bin/../lib/gcc/x86_64-linux-gnu/13.0.0/
-D_GNU_SOURCE -isystem /opt/compiler-explorer/libs/boost_1_80_0 <source> -quiet
-dumpdir /app/ -dumpbase output.cpp -dumpbase-ext .cpp -masm=intel
-mtune=generic -march=x86-64 -g -std=c++20 -version -fdiagnostics-color=always
-o /app/output.s
GNU C++20
(Compiler-Explorer-Build-gcc-895dd027d5dda51a95d242aec8a49a6dfa5db58d-binutils-2.38)
version 13.0.0 20221007 (experimental) (x86_64-linux-gnu)
compiled by GNU C version 9.4.0, GMP version 6.2.1, MPFR version 4.1.0,
MPC version 1.2.1, isl version isl-0.24-GMP
