C++ named requirements: ConstexprIterator

A ConstexprIterator is a LegacyIterator
that can be used during constant expression evaluation.

Requirements

The type It satisfies ConstexprIterator if

• The type It satisfies Iterator

And, for every

• foo, an operation on It that is required to be supported by Iterator,
• args..., a set of arguments to foo that meets the requirements for that operation,

Then

• foo(args...) may be used in a constant expression if args... can also be used.

Standard library

The following standard library types are ConstexprIterators.

• array::iterator and array::const_iterator.
• basic_string_view::iterator.
• span::iterator.
• vector::iterator and vector::const_iterator.