Function parseUInt

extras/catch_amalgamated.cpp:5381–5405

namespace Catch {

    Optional<unsigned int> parseUInt(std::string const& input, int base) {
        auto trimmed = trim( input );
        // std::stoull is annoying and accepts numbers starting with '-',
        // it just negates them into unsigned int
        if ( trimmed.empty() || trimmed[0] == '-' ) {
            return {};
        }

        CATCH_TRY {
            size_t pos = 0;
            const auto ret = std::stoull( trimmed, &pos, base );

            // We did not consume the whole input, so there is an issue
            // This can be bunch of different stuff, like multiple numbers
            // in the input, or invalid digits/characters and so on. Either
            // way, we do not want to return the partially parsed result.
            if ( pos != trimmed.size() ) {
                return {};
            }
            // Too large
            if ( ret > std::numeric_limits<unsigned int>::max() ) {
                return {};
            }
            return static_cast<unsigned int>(ret);
        }
        CATCH_CATCH_ANON( std::invalid_argument const& ) {
            // no conversion could be performed
        }