Warning C26473

Don't cast between pointer types where the source type and the target type are the same.

C++ Core Guidelines: Type.1: Avoid casts

This rule helps to remove unnecessary or suspicious casts. Obviously, when a type is converted to itself, such a conversion is ineffective. Yet the fact that the cast is used may indicate a subtle design issue or a potential for regression if types change in future. It's always safer to use as few casts as possible.

Remarks

• This rule is implemented for static casts and reinterpret casts, and checks only pointer types.

Example

dangerously generic lookup

gsl::span<server> servers_; template<class T> server* resolve_server(T tag) noexcept { auto p = reinterpret_cast<server*>(tag); // C26473, also 26490 NO_REINTERPRET_CAST return p >= &(*servers_.begin()) && p < &(*servers_.end()) ? p : nullptr; } void promote(server *s, int index) noexcept { auto s0 = resolve_server(s); auto s1 = resolve_server(index); if (s0 && s1) std::swap(s0, s1); } 

dangerously generic lookup - reworked

// ... server* resolve_server(server *p) noexcept { return p >= &(*servers_.begin()) && p < &(*servers_.end()) ? p : nullptr; } server* resolve_server(ptrdiff_t i) noexcept { return !servers_.empty() && i >= 0 && i < servers_.size() ? &servers_[i] : nullptr; } // ...