+ /// Construct a location from \a b to \a e.
+ location (const position& b, const position& e)
+ : begin (b)
+ , end (e)
+ {
+ }
+
+ /// Construct a 0-width location in \a p.
+ explicit location (const position& p = position ())
+ : begin (p)
+ , end (p)
+ {
+ }
+
+ /// Construct a 0-width location in \a f, \a l, \a c.
+ explicit location (]b4_percent_define_get([[filename_type]])[* f,
+ unsigned int l = ]b4_location_initial_line[u,
+ unsigned int c = ]b4_location_initial_column[u)
+ : begin (f, l, c)
+ , end (f, l, c)