A concept that indicates ToType can be constructed from a FromType, via ToType::from(FromType).

This concept is rarely used directly, instead prefer to use the sus::construct::Into concept, as it also supports identity transformations.

When a type is From<T, O>, it is also Into<O, T>. Then a variable o of type O can be explicitly converted to T, with type deduction, via sus::into(o).

It is only possible to satisfy this concept for ToType that is not a reference, as it needs to be able to construct ToType.

Arrays

It's possible to convert from an array, in which case From<T, O(&)[]> is satisfied. To do so, implement from() as a templated method, with a size_t template parameter for the size of the incoming array. For example:

// sus::construct::From<Slice<T>, O[]> trait.
template <size_t N>
static constexpr inline Slice from(T (&data)[N]) {
  return Slice(data, N);
}