Compiler confused when compiling template variable initialized by lambda-expression with default parameter. #33352
Description
| Bugzilla Link | 34005 |
| Version | trunk |
| OS | All |
| Reporter | LLVM Bugzilla Contributor |
| CC | @Quuxplusone |
Extended Description
The code below fail to be compile.
// prog.cc
template<int> struct X {};
template<int n> constexpr void f(X<n>) {}
template<typename> constexpr int v = [](int r = 0l) constexpr { return r; }();
int main() {
f<v<int>>(X<0>());
}$ clang++ -std=c++1z prog.cc
prog.cc:6:5: error: no matching function for call to 'f'
f<v<int>>(X<0>());
^~~~~~~~~
prog.cc:2:32: note: candidate function not viable: no known conversion from 'X<...>' to 'X<...>' for 1st argument
template<int n> constexpr void f(X<n>) {}
^
1 error generated.
I think v<T> is always 0, so f<v<int>>(X<0>()) should match f<0>(X<0>);
And if lambda's default parameter type is int,
template<typename> constexpr int v = [](int r = 0) constexpr { return r; }();There are no errors.
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