pointer vs reference
in [Visual C]
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From: Eric Kaplan on 4 Apr 2008 20:20 what are the difference between the following 4 variables? const int * start int* const start int const& start Request(int const& start);
From: Eric Kaplan on 4 Apr 2008 20:27 more specific - for passing parameter, what's different between & OR * pointer vs reference ?? Request(string const& start, string const& end); Request(string const* start, string const* end);
From: Eric Kaplan on 4 Apr 2008 20:30 I suppose the following is exact same thing right? int * const start int const * start both means the pointer is constant - (pointer always point to same address)
From: Alf P. Steinbach on 4 Apr 2008 20:49 * Eric Kaplan: > what are the difference between the following 4 variables? > > const int * start > int* const start > int const& start > Request(int const& start); The last line does not declare a variable. And the three lines above are syntactically invalid as declarations, so do not declare variables either. So instead of 4 variables, you have no variables. Cheers, & hth., - Alf
From: Alf P. Steinbach on 4 Apr 2008 20:54
* Eric Kaplan: > more specific - for passing parameter, what's different between > > & OR * > > pointer vs reference ?? > > Request(string const& start, string const& end); > Request(string const* start, string const* end); The first one essentially communicates (to programmers) that you're not supporting null-pointers, and it lets you call the function with any arguments that can be implicitly converted to string, such a literal strings. The second communicates that you're supporting null-pointer arguments, does not support implicit conversion to string, and yields more awkward notation. With some argument type other than string, the second form might instead communicate that the function expects pointers to dynamically allocated objects, without taking ownership (for ownership use smart pointers). Cheers, & hth., - Alf |