Method increment

tests/lib/testlib.h:1850–1855

    }

    char increment() {
        char c;
        if ((c = buffer[bufferPos++]) == LF)
            line++;
        return c;
    }

public:
    BufferedFileInputStreamReader(std::FILE *file, const std::string &name) : file(file), name(name), line(1) {