Some compiler errors missed when "did you mean" is suggested.

[bakercp]

Here is a minimal example:

void setup() {
    std::string s("Hello World!");
    s.substring(0);
}

This produces the following error:

HelloWorld:4:7: error: no member named 'substring' in 'std::basic_string<char>'; did you mean 'substr'?
    s.substring(0);
      ^~~~~~~~~
      substr
/usr/include/c++/4.2.1/bits/basic_string.h:1921:7: note: 'substr' declared here
      substr(size_type __pos = 0, size_type __n = npos) const
      ^
1 error generated.

This should be parsed.