1 // PR c++/66635 2 // { dg-do compile { target c++11 } } 3 4 #include <cassert> 5 6 struct Foo { FooFoo7 constexpr Foo(const unsigned i) : val(i) {} 8 constexpr Foo operator-(const Foo &rhs) const { 9 return assert(val >= rhs.val), Foo(val - rhs.val); // { dg-error "call to non-.constexpr." } 10 } 11 unsigned val; 12 }; 13 14 constexpr Foo foo(Foo(1) - Foo(2)); // { dg-message "in .constexpr. expansion of " } 15