No default value for objects containing range components

[cmacmackin]

It is impossible to create an uninitialised object value if the object contains a range component that does not include zero. Curiously, one is allowed to use an uninitialised range variable.

Example

type
  R = range[1..10]
  Obj = object
    r: R

var
  rVal: R  # Works fine
  objVal: Obj  # Compile-time error

Current Output

Compile-time error:

range.nim(8, 3) Error: The Obj type doesn't have a default value. The following fields must be initialized: r.

Expected Output

Compile without error

Possible Solution

This is beyond my knowledge of how the compiler works.

Additional Information

The code compiled as of v1.2.0 but failed as of v1.2.2.

This problem initially came to my attention because the marshal.store procedure relies on being able to do this.

Working:

$ nim -v
Nim Compiler Version 1.0.4 [Linux: amd64]
Compiled at 2019-11-27
Copyright (c) 2006-2019 by Andreas Rumpf

active boot switches: -d:release

$ nim -v
Nim Compiler Version 1.2.0 [Linux: amd64]
Compiled at 2020-04-03
Copyright (c) 2006-2020 by Andreas Rumpf

active boot switches: -d:release

Failing:

$ nim -v
Nim Compiler Version 1.2.2 [Linux: amd64]
Compiled at 2020-06-16
Copyright (c) 2006-2020 by Andreas Rumpf

active boot switches: -d:release

$ nim -v
Nim Compiler Version 1.4.2 [Linux: amd64]
Compiled at 2020-11-30
Copyright (c) 2006-2020 by Andreas Rumpf

git hash: 3fb5157ab1b666a5a5c34efde0f357a82d433d04
active boot switches: -d:release

$ nim -v
Nim Compiler Version 1.5.1 [Linux: amd64]
Compiled at 2021-01-18
Copyright (c) 2006-2021 by Andreas Rumpf

git hash: 6c07b0a1f8daf96078ae68b83ead1d48675969d7
active boot switches: -d:release

[timotheecour]

related: nim-lang/RFCs#290