pragma pragma

The pragma pragma can be used to declare user defined pragmas. This is useful because Nim’s templates and macros do not affect pragmas. User defined pragmas are in a different module-wide scope than all other symbols. They cannot be imported from a module.

Example:

when appType == "lib":
  {.pragma: rtl, exportc, dynlib, cdecl.}
else:
  {.pragma: rtl, importc, dynlib: "client.dll", cdecl.}
proc p*(a, b: int): int {.rtl.} =
  result = a+b

In the example a new pragma named rtl is introduced that either imports a symbol from a dynamic library or exports the symbol for dynamic library generation.