Difference between cast(T)x and to!T(x)

cast(T)x does a few types of conversions as guaranteed by the language. These include:

• dynamic casts converting between class / interface types, provided by the runtime
• numeric type casts, eg double to short
• array type casts, eg int[] to ubyte[]
• forcing an alias this conversion that would otherwise not be forced
• type system-only conversions, especially around const and shared

to!T(x) does a number of other conversions, most notably to and from strings.