[C ++] Static detection of printf Compiler

The format string of C is often used. The gcc/clang extension can detect strings and variable parameters. If the parameters do not match, the warning will pop up.

If it is manually written, you need to add a bit of code, otherwise it will not be detected.

1. variable parameters

Void my_printf (const char * format ,...)_ Attribute _ (format (printf, 1, 2 )))

1 indicates the subscript of the parameter where the format string is located (starting from 1 );

2 indicates the subscript starting with the variable parameter.

2. va_list

Void my_print (const char * format, va_list args)_ Attribute _ (format (printf, 1, 0 )))

If it is va_list, enter 0 in the second index.

3. this call

This call, such as C ++,This is the first function member.Don't forget this.