https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67084
Bug ID: 67084
Summary: [c++-concepts] Matching of variable template
declarations ignores constraints
Product: gcc
Version: c++-concepts
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: Casey at Carter dot net
Target Milestone: ---
Created attachment 36102
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36102&action=edit
Test case
The two declarations of p<T> should be distinct due to having different
constraints:
template <class T>
constexpr bool p = true;
template <class T>
requires true
constexpr bool p<T> = false;
template <class T>
requires true && false
constexpr bool p<T> = true;
Compiling this program with r226419 results in:
~/concept-gcc/bin/g++ -std=gnu++1z foo.cpp -c
foo.cpp:10:16: error: redefinition of ‘const bool p<T>’
constexpr bool p<T> = true;
^
foo.cpp:6:16: note: ‘constexpr const bool p<T>’ previously declared here
constexpr bool p<T> = false;
^
foo.cpp:10:16: internal compiler error: in set_constraints, at cp/pt.c:23421
constexpr bool p<T> = true;
^
0x63ae8d set_constraints(tree_node*, tree_node*)
../../gcc/cp/pt.c:23421
0x673e91 process_partial_specialization
../../gcc/cp/pt.c:4728
0x675467 push_template_decl_real(tree_node*, bool)
../../gcc/cp/pt.c:5250
0x6214c4 start_decl(cp_declarator const*, cp_decl_specifier_seq*, int,
tree_node*, tree_node*, tree_node**)
../../gcc/cp/decl.c:4919
0x710720 cp_parser_init_declarator
../../gcc/cp/parser.c:17728
0x7113c4 cp_parser_single_declaration
../../gcc/cp/parser.c:24892
0x71155b cp_parser_template_declaration_after_parameters
../../gcc/cp/parser.c:24509
0x712104 cp_parser_explicit_template_declaration
../../gcc/cp/parser.c:24744
0x712104 cp_parser_template_declaration_after_export
../../gcc/cp/parser.c:24762
0x718aa9 cp_parser_declaration
../../gcc/cp/parser.c:11416
0x7170fa cp_parser_declaration_seq_opt
../../gcc/cp/parser.c:11338
0x717411 cp_parser_translation_unit
../../gcc/cp/parser.c:4153
0x717411 c_parse_file()
../../gcc/cp/parser.c:34295
0x85ea22 c_common_parse_file()
../../gcc/c-family/c-opts.c:1059
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
An equivalent program with class templates or function templates overloaded
similarly does compile correctly.
