Re: Why this works?
Rui Maciel <rui.maciel@gmail.com> wrote:
The compiler can ignore scenarios such as calls to exit(), throwing
exceptions, or invoking functions that do not return, and check which code
path doesn't include a properly formatted return statement. It's better if
the compiler requires unnecessary return statements than it is to support
invalid constructs such as returning uninitialized references of objects
that don't exist.
AFAIK C++ inherits this optionality of a return value from C. I'm guessing
that it exists in C because in the 70's they didn't want to force the
programmer to increase the size of functions by even one byte if they
absolutely didn't have to.
Nowadays increasing the size of a function by a few bytes due to an
extraneous 'return' might not be a problem, but the thing is, there
might be cases where the 'return' actually takes a lot more than just
a few bytes.
The return value might in fact be very large, like several kilobytes.
*Creating* the return value might be very complicated or laborious
(such as it being an object with a mandatory constructor that takes
hundreds of mandatory parameters.) Being forced to construct such a
complicated object can in some cases be completely unnecessary, for
example in situations like
SomeType foo()
{
if(something)
someCodeHere;
throw("this should never happen!");
}
If constructing an object of 'SomeType' is extremely complicated,
having to construct a dummy object that will never be executed would
be completely unnecessary.
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