diff options
Diffstat (limited to 'compat/borrowed-ptr.hpp')
| -rw-r--r-- | compat/borrowed-ptr.hpp | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/compat/borrowed-ptr.hpp b/compat/borrowed-ptr.hpp index 5caa2261..d13d8ee2 100644 --- a/compat/borrowed-ptr.hpp +++ b/compat/borrowed-ptr.hpp @@ -28,20 +28,23 @@ concept StaticCastable = requires(From* from) { namespace floormat { -template<typename T, typename U> +template<typename U, typename T> bptr<U> static_pointer_cast(const bptr<T>& p) noexcept { - static_assert(detail_borrowed_ptr::StaticCastable<T, U>); - - if (p.blk) [[likely]] + // hack to generate better error message + if constexpr (detail_borrowed_ptr::StaticCastable<T, U>) { - if (auto* ptr = p.blk->_ptr) + if (p.blk && p.blk->_ptr) [[likely]] { fm_bptr_assert(p.casted_ptr); auto* ret = static_cast<U*>(p.casted_ptr); return bptr<U>{DirectInit, ret, p.blk}; } } + else + // concepts can't be forward-declared so use static_assert + static_assert(detail_borrowed_ptr::StaticCastable<T, U>); + return bptr<U>{nullptr}; } |