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digitalmars.D - Re: Null references (oh no, not again!)

Walter Bright Wrote:

When I see code like this I see bugs.

 Foo f;
 if (x < 1) f = new Foo(1);
 else if (x >= 1) f = new Foo(2);

This should not compile IMHO default non nullable is necessary. If using a language with default nullable, I would write this as Foo generateFoo() { if (x < 1) return new Foo(1); else if (x >= 1) return new Foo(2); } This way the compiler has to check that there is a returned value for each path. As the conditions become more complex, the compiler enforcing a return value prevents the result from being null (unless of course you return 0 just to prove a point)
 Foo f;
 ? Or in another form:
 bar(ref Foo f);
 Foo f;
 Java doesn't have ref parameters.

Same problem. The prototype of bar should be Foo bar() if the intent of bar is to return a reference to an instance of Foo. Returning what is conceptually the result of a function in by ref parameters is really nasty way to code IMHO. Alex
Mar 05 2009