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Struct std.typecons.Typedef
Typedef allows the creation of a unique type which is
based on an existing type. Unlike the alias feature,
Typedef ensures the two types are not considered as equals.
Example
alias MyInt = Typedef!int;
static void takeInt(int) { }
static void takeMyInt(MyInt) { }
int i;
takeInt(i); // ok
takeMyInt(i); // fails
MyInt myInt;
takeInt(myInt); // fails
takeMyInt(myInt); // ok
Parameters
| Name | Description |
|---|---|
| init | Optional initial value for the new type. For example:
----
alias MyInt = Typedef!(int, 10);
MyInt myInt;
assert(myInt == 10); // default-initialized to 10
----
|
| cookie | Optional, used to create multiple unique types which are
based on the same origin type T. For example:
----
alias TypeInt1 = Typedef!int;
alias TypeInt2 = Typedef!int;
// The two Typedefs are the same type.
static assert(is(TypeInt1 == TypeInt2));
alias MoneyEuros = Typedef!(float, float.init, "euros");
alias MoneyDollars = Typedef!(float, float.init, "dollars");
// The two Typedefs are not_ the same type.
static assert(!is(MoneyEuros == MoneyDollars));
---- |
Note
If a library routine cannot handle the Typedef type,
you can use the TypedefTypeTypedef wraps.
Authors
Andrei Alexandrescu, Bartosz Milewski, Don Clugston, Shin Fujishiro, Kenji Hara