std_lib_facilities.h:107:8: warning: comparison of unsigned expression < 0 is always false [-Wtautological-compare]
                if (i<0||size()<=i) throw Range_error(i);
                    ~^~
std_lib_facilities.h:113:8: warning: comparison of unsigned expression < 0 is always false [-Wtautological-compare]
                if (i<0||size()<=i) throw Range_error(i);
                    ~^~

// trivially range-checked string (no iterator checking):
struct String : std::string {
    using size_type = std::string::size_type;
//  using string::string;

    char& operator[](unsigned int i) // rather than return at(i);
    {
        if (i<0||size()<=i) throw Range_error(i);
        return std::string::operator[](i);
    }

    const char& operator[](unsigned int i) const
    {
        if (i<0||size()<=i) throw Range_error(i);
        return std::string::operator[](i);
    }
};

{
    "cmd": ["g++", "-Wall", "-Wextra", "-pedantic", "-std=c++11",   "${file}", "-o", "${file_path}/${file_base_name}"],
    "file_regex": "^(..[^:]*):([0-9]+):?([0-9]+)?:? (.*)$",
    "working_dir": "${file_path}",
    "selector": "source.c, source.c++",

    "variants":
    [
        {
            "name": "Run",
            "cmd": ["bash", "-c", "g++ -Wall -Wextra -pedantic -std=c++11 '${file}' -o '${file_path}/${file_base_name}' && '${file_path}/${file_base_name}'"]
        }
    ]
}