rust/compiler/rustc_builtin_macros
Dylan DPC ec8477fea1
Rollup merge of #98337 - c410-f3r:assert-compiler, r=oli-obk
[RFC 2011] Optimize non-consuming operators

Tracking issue: https://github.com/rust-lang/rust/issues/44838
Fifth step of https://github.com/rust-lang/rust/pull/96496

The most non-invasive approach that will probably have very little to no performance impact.

## Current behaviour

Captures are handled "on-the-fly", i.e., they are performed in the same place expressions are located.

```rust
// `let a = 1; let b = 2; assert!(a > 1 && b < 100);`

if !(
  { ***try capture `a` and then return `a`*** } > 1 && { ***try capture `b` and then return `b`*** } < 100
) {
  panic!( ... );
}
```

As such, some overhead is likely to occur (Specially with very large chains of conditions).

## New behaviour for non-consuming operators

When an operator is known to not take `self`, then it is possible to capture variables **AFTER** the condition.

```rust
// `let a = 1; let b = 2; assert!(a > 1 && b < 100);`

if !( a > 1 && b < 100 ) {
  { ***try capture `a`*** }
  { ***try capture `b`*** }
  panic!( ... );
}
```

So the possible impact on the runtime execution time will be diminished.

r? ````@oli-obk````
2022-06-28 15:30:02 +05:30
..
src Rollup merge of #98337 - c410-f3r:assert-compiler, r=oli-obk 2022-06-28 15:30:02 +05:30
Cargo.toml Migrate builtin-macros-requires-cfg-pattern to SessionDiagnostic 2022-06-21 20:10:31 +01:00