What's the bug in the following code:
```d
import std.digest.md;
import std.stdio;
pragma(inline, false) // just in case
string getHash()
{
ubyte[16] hash = [1,2,3,4,5,6,6,78,8,8,7,7,6,3,2,3];
string a = toHexString(hash);
return a;
}
pragma(inline, false) // just in case
void destroystack()
{
writeln("asd","asd","asd","asd","asd","asd");
}
void main()
{
string a = getHash();
destroystack();
writeln(a);
}
```
Hint: when changing
```
string a = toHexString(hash);
return a;
```
to
```
return toHexString(hash);
```
the compiler errors with:
`Error: escaping reference to stack allocated value returned by
toHexString(hash)`.
So:
- the documentation of toHexString says that the overloads
returning a string return a GC allocated string
- the _implementation_ of `string toHexString(...)` does a `new
char[16]`, so GC allocates.
- `string a = toHexString(hash);` calls `char[num*2]
toHexString(...)` instead of `string toHexString(...)`. OOPS.
https://issues.dlang.org/show_bug.cgi?id=16519
I don't know whether this is a compiler bug (choosing the wrong
overload) or a Phobos bug (overloads don't work like that).
How are template overloads involving `string` and
`char[constant]` return values supposed to work?
Still can't believe I am the first one to run into this, what am
I doing wrong?
-Johan
