Rust-GCC / Rust-GCC/gccrs

Empty ```TupleStructPattern``` assumed to be function call

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#2,846 3 comments 0 reactions 0 assignees View on GitHub

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bug
Dominant language
C++
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Forks
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Avg merge
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Merged PRs (30d)
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Description

I tried this code:

struct S();

pub fn main() {
    match S() {
        S() => {}
    }
}

I expected to see this happen: no error

Instead, this happened:

<source>:5:9: error: expected tuple struct or tuple variant, found associated function [E0164]
    5 |         S() => {}
      |         ^
      |         function calls are not allowed in patterns

Contributor guide

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First steps

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by compiling the Rust snippet in the issue and tracing how the compiler handles the empty S() pattern in a match. Done means the example compiles without the E0164 diagnostic and preserves the expected pattern-matching behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp, rust
Domain
compilers
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

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