basic_static_string::assign (6 of 12 overloads)

Replace the contents.

BOOST_STATIC_STRING_CPP14_CONSTEXPR basic_static_string&
assign(
    const_pointer s,
    size_type count);

Replace the contents with the first count characters of s, including nulls.

Type	Thrown On
`std::length_error`	if `count > max_size()`

*this