On 4/26/2012 12:47 AM, Timon Gehr wrote:
On 04/26/2012 05:44 AM, Walter Bright wrote:
A subtle but nasty problem - are default arguments part of the type, or
part of the declaration?
See http://d.puremagic.com/issues/show_bug.cgi?id=3866
Currently, they are both,
That is how it should be.
which leads to the nasty behavior in the bug report.
It contributes, but it is not the main cause.
The problem centers around name mangling. If two types mangle the same,
then they are the same type.
Then they are equal types.
This is simply not tenable. What defines when they are "equal" types and when
they are "not equal"? Consider a pointer to a function. Are the default
arguments part of its type? If it compares "equal" to another type without
default arguments, which is the real type (such as the result of ?:) ?
But default arguments are not part of the
mangled string. Hence the schizophrenic behavior.
The schizophrenic behavior occurs because the types cross-talk. Are mangled
names kept unique in the compiler or what is the implementation issue exactly?
It's a conceptual issue. When is one type the same as another, and when is it
not?
