Structs and assiciative arrays

[Simen Haugen]

I just hunted quite some time for a bug that was because I'm using structs
as the key for associative arrays.
It worked without problem for a long time, and now after I added a string to
the struct the associative array wouldnt work.

I found in the documentation:
" If the KeyType is a struct type, a default mechanism is used to compute
the hash and comparisons of it based on the binary data within the struct
value. A custom mechanism can be used by providing the following functions
as struct members:"
uint toHash();
int opCmp(KeyType* s);

After I implemented these everything worked fine.

I wrote a simple test to check if it was because of the string, but
everything worked in my testcase. So I'm wondering what actually broke it...