Synopsis

(Required) The controlling expression of a generic selection shall have an essential type that matches its standard type.

Enabled by default

Yes

Severity/Certainty

Medium/Medium

Full description

Found generic selection not using an essential type that matches its standard type.

Coding standards

Code examples

The following code example fails the check and will give a warning:

void handle_short(short s);
void handle_int(int i);

#define filter_ints(X) ( _Generic((X) \
 , short: handle_short \
 , int : handle_int ) (X) )

void example(void) {
  short s16 = 0;
  
  /* Non-compliant */
  filter_ints (s16 + s16); /* Selects int, essentially short */
}

The following code example passes the check and will not give a warning about this issue:

void handle_short(short s);
void handle_int(int i);

#define filter_ints(X) ( _Generic((X) \
 , short: handle_short \
 , int : handle_int ) (X) )

void example(void) {
  short s16 = 0;
  
  /* Compliant */
  filter_ints (s16);
}