http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48500
Summary: Regression: Failing to convert template argument to
concrete type, in C++0x mode.
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: jyass...@gcc.gnu.org
CC: ja...@gcc.gnu.org
This shows up in template functions that try to pass a value whose type is a
template argument to a function that expects one or more concrete types. The
code compiles in gcc-4.5, produces an error in 4.6.0 and gcc-4_6-branch, and
produces an ICE in trunk. All of them succeed in C++98 mode.
$ cat test.cc
struct linked_ptr {
};
template <typename T> linked_ptr make_linked_ptr(T* ptr);
struct Concrete;
struct NewedClass {
NewedClass(const Concrete& req){}
};
template<typename ArgT> void AddObjToChange(const ArgT& req) {
linked_ptr p = make_linked_ptr(new NewedClass(req));
}
$ g++-mp-4.5 -c test.cc -std=gnu++0x
$ g++-mp-4.6 -c test.cc -std=gnu++0x # Or gcc-4_6-branch at r172074
test.cc: In function 'void AddObjToChange(const ArgT&)':
test.cc:9:53: error: no matching function for call to
'NewedClass::NewedClass(const ArgT&)'
test.cc:9:53: note: candidates are:
test.cc:6:3: note: NewedClass::NewedClass(const Concrete&)
test.cc:6:3: note: no known conversion for argument 1 from 'const ArgT' to
'const Concrete&'
test.cc:5:8: note: constexpr NewedClass::NewedClass(const NewedClass&)
test.cc:5:8: note: no known conversion for argument 1 from 'const ArgT' to
'const NewedClass&'
test.cc:5:8: note: constexpr NewedClass::NewedClass(NewedClass&&)
test.cc:5:8: note: no known conversion for argument 1 from 'const ArgT' to
'NewedClass&&'
$ trunk-r172073/g++ -std=gnu++0x -c test.cc
test.cc: In function ‘void AddObjToChange(const ArgT&)’:
test.cc:9:53: internal compiler error: tree check: expected record_type or
union_type or qual_union_type, have template_type_parm in lookup_base, at
cp/search.c:212
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
$
An error in similar code went away with the fix to PR48319.
