Function isWhitespace

unittests/catch.hpp:5266–5269

namespace Catch { namespace clara { namespace TextFlow {

    inline auto isWhitespace( char c ) -> bool {
        static std::string chars = " \t\n\r";
        return chars.find( c ) != std::string::npos;
    }
    inline auto isBreakableBefore( char c ) -> bool {
        static std::string chars = "[({<|";
        return chars.find( c ) != std::string::npos;