format_visitor.h:2:  private: should be indented +1 space inside class FormatVisitor  [whitespace/indent] [3]
format_visitor.h:6:  public: should be indented +1 space inside class FormatVisitor  [whitespace/indent] [3]
format_visitor.h:6:  "public:" should be preceded by a blank line  [whitespace/blank_line] [3]
format_visitor.h:68:  { should almost always be at the end of the previous line  [whitespace/braces] [4]
format_visitor.h:67:  Add #include <string> for string  [build/include_what_you_use] [4]
format_visitor.h:67:  Add #include <vector> for vector<>  [build/include_what_you_use] [4]
format_visitor.h:71:  Could not find a newline character at the end of the file.  [whitespace/ending_newline] [5]
Done processing format_visitor.h
Total errors found: 7