is, as, Casting

is (Type Query)

See Cpp2 is:

• obj is Int (i.e. a type)
• objPtr is T* instead of dynamic_cast<T*>(objPtr) != NullPtr
• obj is cilia::Array (i.e. a template)
• obj is cilia::Integer (i.e. a concept)

TODO Also support value query?

as

See Cpp2 as

• obj as T instead of T(obj)
• objPtr as T* instead of dynamic_cast<T*>(objPtr)
• With Variant v where T is one alternative:
  v as T instead of std::get<T>(v)
• With Any a:
  a as T instead of std::any_cast<T>(a)
• With Optional<T> o:
  o as T instead of o.value()

Constructor Casting

• Float(3)
• Casting via constructor is explicit by default, implicit as option.
• No classic C-style casting: (Float) 3

Classical C++ Casts

All of these also work for smart pointers (T^, T+, T-), replacing std::*_pointer_cast.

• staticCastTo<T>(...) instead of static_cast<T>(...)
• dynamicCastTo<T>(...) instead of dynamic_cast<T>(...)
  • But typically objPtr as T* is preferred.
• castToMutable<T>(...) instead of const_cast<T>(...),
  • typically used as castToMutable(...), as the type is inferred.
• reinterpretCastTo<T>(...) instead of reinterpret_cast<T>(...)
• castTo<T>(...)?
  • A general, safe cast, i.e. like as, but in function syntax.
• Other casts of the C++ standard library (and GSL):
  • bitCastTo<T>(...) instead of std::bit_cast<T>(...)
  • anyCastTo<T>(a) instead of std::any_cast<T>(a)
    • But typically a as T is preferred.
  • durationCastTo<T>(d) instead of std::chrono::duration_cast<T>(d)
  • timePointCastTo<T>(t) instead of std::chrono::time_point_cast<T>(t)
  • narrowCastTo<T>(...) instead of gsl::narrow_cast<T>(...) (unchecked)
  • narrowTo<T>(...) instead of gsl::narrow<T>(...) (checked)