I think : Ýmmutable, type automatic moments. Because, it is StorageClass.
Example : import std.stdio; void main() { immutable a = 3, b = 4.2, c = true; writeln(typeof(a).stringof,typeof(b).stringof,typeof(c).stringof); } or import std.stdio; void main() { auto a = 3, b = 4.2, c = true; writeln(typeof(a).stringof,typeof(b).stringof,typeof(c).stringof); } Keywords(StorageClass): abstract auto const deprecated extern final immutable shared nothrow override pure scope static synchronized I don't know English. I'm sorry if misspelled.