Error: internal error: getTypeDescAux(tyFromExpr) when using auto + arc, works with refc

[arkanoid87]

What happened?

# works with --gc:refc
# Error: internal error: getTypeDescAux(tyFromExpr) with --gc:arc

func hakunaMatata[N, D](n: N, d: D): auto =
    if d.float > 0: (n/d) else: 0.0.auto

echo hakunaMatata(42.0, 0.42)

Nim Version

Nim Compiler Version 1.6.8 [Linux: amd64]
Compiled at 2022-09-27
Copyright (c) 2006-2021 by Andreas Rumpf

git hash: c9f46ca8c9eeca8b5f68591b1abe14b962f80a4c
active boot switches: -d:release

Current Standard Output Logs

Error: internal error: getTypeDescAux(tyFromExpr)
No stack traceback available

Expected Standard Output Logs

100.0

Possible Solution

No response

Additional Information

No response

[metagn]

Compiles with 0.0.auto -> 0.0. Don't know what 0.0.auto is supposed to mean, it's not needed as far as I can tell:

func hakunaMatata[N, D](n: N, d: D): auto =
    if d.float > 0: (n/d) else: 0.0

echo hakunaMatata(42.0, 0.42).type # float
echo hakunaMatata(42f32, 3f32).type # float32

[bung87]

where the 0.0.auto goes in compiler? from my view auto is not suitable for a dotcall

[Vindaar]

where the 0.0.auto goes in compiler? from my view auto is not suitable for a dotcall

I would assume the symbol auto will be mapped to an implicit generic. Therefore the dot call for 0.0.auto just converts the literal to the implicit generic that auto was determined to be.

edit: I mean that's what I would understand the syntax to imply.

[bung87]

I debug in serveral places, in the end I start from semIf , found it's

proc semExprBranch(c: PContext, n: PNode; flags: TExprFlags = {}; expectedType: PType = nil): PNode =
  result = semExpr(c, n, flags, expectedType)
  echo result.typ

outputs typeof(auto(0.0))