Is it possible to restrict a type parameter to be a reference type? I see you can use T(!new) but I’m looking for the opposite.

Question

Is it possible to restrict a type parameter to be a reference type? I see you can use T(!new) but I’m looking for the opposite.

Answer

No. The only restrictions available (as of version 3.7.3) are

• T(==) - type supports equality
• T(0) - type is auto-initializable
• T(00) - type is non-empty
• T(!new) - type may not be a reference type or contain a reference type

See the appropriate section of the reference manual for more information.