10.4. decltype macro and template function annotation

The TEMPLATES module implements template instantiation utilities for daslang code generation. It supports stamping out parameterized code patterns with type and value substitution.

See also Template application helpers for template substitution and code generation.

All functions and symbols are in “templates” module, use require to get access to it.

require daslib/templates

10.4.1. Function annotations

templates::template

This macro is used to remove unused (template) arguments from the instantiation of the generic function. When [template(x)] is specified, the argument x is removed from the function call, but the type of the instance remains. The call where the function is instanciated is adjusted as well. For example:

[template (a), sideeffects]
def boo ( x : int; a : auto(TT) )   // when boo(1,type<int>)
    return "{x}_{typeinfo(typename type<TT>)}"
...
boo(1,type<int>) // will be replaced with boo(1). instace will print "1_int"

10.4.2. Call macros

templates::decltype

This macro returns ast::TypeDecl for the corresponding expression. For example:

let x = 1
let y <- decltype(x) // [[TypeDecl() baseType==Type tInt, flags=TypeDeclFlags constant | TypeDeclFlags ref]]

templates::decltype_noref

This macro returns TypeDecl for the corresponding expression, minus the ref (&) portion.