Function test_stl_conversions

scripts/test_stringzilla.cpp:1884–1913

* @brief Constructs StringZilla classes from STL and vice-versa to ensure that the conversions are working. */

 *  @brief  Constructs StringZilla classes from STL and vice-versa to ensure that the conversions are working.
 */
void test_stl_conversions() {
    // From a mutable STL string to StringZilla and vice-versa.
    {
        std::string stl {"hello"};
        sz::string sz = stl;
        sz::string_view szv = stl;
        sz::string_span szs = stl;
        stl = sz;
        stl = szv;
        stl = szs;
    }
    // From an immutable STL string to StringZilla.
    {
        std::string const stl {"hello"};
        sz::string sz = stl;
        sz::string_view szv = stl;
        sz_unused_(sz);
        sz_unused_(szv);
    }
#if SZ_IS_CPP17_ && defined(__cpp_lib_string_view)
    // From STL `string_view` to StringZilla and vice-versa.
    {
        std::string_view stl {"hello"};
        sz::string sz = stl;
        sz::string_view szv = stl;
        stl = sz;
        stl = szv;
    }
#endif
}

/**
 *  @brief The sum of an arithmetic progression.