template treated as template(): untyped when using in template without bracket

[slangmgh]

Example

type Buffer = object
   lines: seq[string]

var buffer: Buffer

proc p1(ss: seq[string]) = discard
template code_lines: untyped = buffer.lines
template p2() = p1(code_lines)    # change `template` to `proc` make the compiler success

p2()

Current Output

D:\Tool\Nim\tmp\a12.nim(10, 3) Error: type mismatch: got <template (): untyped>
but expected one of:
proc p1(ss: seq[string])
  first type mismatch at position: 1
  required type for ss: seq[string]
  but expression 'code_lines' is of type: template (): untyped

expression: p1(code_lines)

Expected Output

compile success.

Possible Solution

change the second template to proc

Additional Information

$ nim -v
Nim Compiler Version 1.3.3 [Windows: i386]
Compiled at 2020-05-13
Copyright (c) 2006-2020 by Andreas Rumpf

active boot switches: -d:release

[kaushalmodi]

I think that the behavior to see is expected. You are trying to expand the code_lines template, right? If so, I think that it should have the parens.

Your code modified: https://play.nim-lang.org/#ix=2lRb

[slangmgh]

But the following code is ok. I think people will be confused why the proc cannot change to template.

proc p2()  = p1(code_lines)

[slangmgh]

This is the same bug with #14332, add {.dirty.} to the template can fix the problem too.

[metagn]

Duplicate of #13515

[timotheecour]

closing as duplicate