In C++, the index operator for maps will either return a
reference to the existing value if the key can be found, or a
reference to a new, default-initialized value if one with the
given key cannot be found.
In D, an exception is thrown instead when a value with the given
key cannot be found, similar to unordered_map::at in C++. So if I
want to mimic the same behavior (get or initialize to default), I
have to do something like
// Assume bar is some associative array of type Foo[string]
Foo* value = key in bar;
if (value) {
bar[key] = Foo.init;
value = &bar[key];
}
This seems sub-optimal, given that in involves three hashes (two
lookups and one insertion). Is there a more efficient or cleaner
way to do so?
