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| author | lcnr <rust@lcnr.de> | 2022-11-14 17:42:46 +0100 |
|---|---|---|
| committer | lcnr <rust@lcnr.de> | 2022-11-15 13:34:08 +0100 |
| commit | 45f441a7b41d09bb78b0ba3e260d2c868ef6add7 (patch) | |
| tree | 0ab27b9bde513532c7f3b006f74148a246e85ad1 /compiler/rustc_infer/src | |
| parent | ca92d90b5917e7176d5ff06607a2cd5352c088d3 (diff) | |
| download | rust-45f441a7b41d09bb78b0ba3e260d2c868ef6add7.tar.gz rust-45f441a7b41d09bb78b0ba3e260d2c868ef6add7.zip | |
nll: correctly deal with bivariance
Diffstat (limited to 'compiler/rustc_infer/src')
| -rw-r--r-- | compiler/rustc_infer/src/infer/nll_relate/mod.rs | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/compiler/rustc_infer/src/infer/nll_relate/mod.rs b/compiler/rustc_infer/src/infer/nll_relate/mod.rs index 600f94f095e..74b2fb613b7 100644 --- a/compiler/rustc_infer/src/infer/nll_relate/mod.rs +++ b/compiler/rustc_infer/src/infer/nll_relate/mod.rs @@ -556,8 +556,12 @@ where self.ambient_variance_info = self.ambient_variance_info.xform(info); debug!(?self.ambient_variance); - - let r = self.relate(a, b)?; + // In a bivariant context this always succeeds. + let r = if self.ambient_variance == ty::Variance::Bivariant { + a + } else { + self.relate(a, b)? + }; self.ambient_variance = old_ambient_variance; |