https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91008
Bug ID: 91008
Summary: error redeclaring the same type involving a non-type
template argument
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
The three typedefs below all define the same type yet they are rejected.
$ cat t.C && gcc -O2 -c -Wall -Wpedantic -std=c++2a t.C
struct A
{
constexpr A (int i = 0): i (i + 1) { }
int i;
};
struct B { A a[2]; };
template <struct B> struct X { };
typedef X<B{ }> XB;
typedef X<B{ 0 }> XB;
typedef X<B{ 0, 0 }> XB;
t.C:12:19: error: conflicting declaration ‘typedef struct X<B{A [2]{A{1},
A{1}}}> XB’
12 | typedef X<B{ 0 }> XB;
| ^~
t.C:11:17: note: previous declaration as ‘typedef struct X<B{A [2]{A{1}}}> XB’
11 | typedef X<B{ }> XB;
| ^~
t.C:13:22: error: conflicting declaration ‘typedef struct X<B{A [2]{A{1},
A{1}}}> XB’
13 | typedef X<B{ 0, 0 }> XB;
| ^~
t.C:11:17: note: previous declaration as ‘typedef struct X<B{A [2]{A{1}}}> XB’
11 | typedef X<B{ }> XB;
| ^~
