https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92211
Bug ID: 92211
Summary: Lamdas in unevaluated context bug
Product: gcc
Version: 9.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: pilarlatiesa at gmail dot com
Target Milestone: ---
This code compiles fine (https://godbolt.org/z/JeuX4m):
template<int dim, int rank>
struct Tensor {};
template<int dim, int rank>
double mag(Tensor<dim, rank> const &) { return 0.0; }
template<int dim, int rank>
using TMag = decltype([](Tensor<dim, rank> const &x) { return mag(x); });
template<typename TOp>
class UnaryExpr
{
TOp const Op = {};
};
UnaryExpr<TMag<0, 666>> fn() { return {}; }
This one does not (https://godbolt.org/z/rD3v8E):
template<int dim, int rank>
struct Tensor {};
template<int dim, int rank>
double mag(Tensor<dim, rank> const &) { return 0.0; }
template<int dim, int rank>
using TMag = decltype([](Tensor<dim, rank> const &x) { return mag(x); });
template<typename TOp>
class UnaryExpr
{
TOp const Op = {};
};
template<int dim, int rank>
UnaryExpr<TMag<dim, rank>> fn() { return {}; }
This one causes GGC to segfault (https://godbolt.org/z/8GsGYe)
template<int dim, int rank>
struct Tensor {};
template<int dim, int rank>
double mag(Tensor<dim, rank> const &) { return 0.0; }
template<int dim, int rank>
using TMag = decltype([](Tensor<dim, rank> const &x) { return mag(x); });
template<typename TOp>
class UnaryExpr
{
TOp const Op = {};
};
template<int dim, int rank, typename T = TMag<dim, rank>>
UnaryExpr<T> fn() { return {}; }
