stringview lite: A single-file header-only version of a C++17-like stringview for C++98, C++11 and later

Compile and run

`stringview` literals `sv` and `sv`

Cooperation between `std::string` and `nonstd::stringview`

Standard selection macro

Select `std::stringview` or `nonstd::stringview`

Disable exceptions

Add or omit literal operators `sv` and `sv`

Omit cooperation between `std::string`–`nonstd::stringview`

A.1 Compile-time information

A.2 string-view lite test specification