Merge #843

843: Impl generics r=matklad a=flodiebold

This handles type parameters on impls when typing method calls.

~One remaining problem is that the autoderefs aren't applied during the unification of the method receiver type with the actual receiver type, which means that the type parameters are only correctly inferred if no autoderefs happened.~

Co-authored-by: Florian Diebold <[email protected]>

3 files changed, 82 insertions, 27 deletions

diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
index 626f31252..d1ce87b0a 100644
--- a/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_generic_chain.snap
@@ -1,36 +1,36 @@
 ---
-created: "2019-01-27T14:52:29.938713255+00:00"
-creator: [email protected]
-expression: "&result"
+created: "2019-02-16T20:53:59.655361804Z"
+creator: [email protected]
 source: crates/ra_hir/src/ty/tests.rs
+expression: "&result"
 ---
-[53; 57) 'self': A<[unknown]>
-[65; 87) '{     ...     }': [unknown]
-[75; 79) 'self': A<[unknown]>
-[75; 81) 'self.x': [unknown]
+[53; 57) 'self': A<T2>
+[65; 87) '{     ...     }': T2
+[75; 79) 'self': A<T2>
+[75; 81) 'self.x': T2
 [99; 100) 't': T
 [110; 115) '{ t }': T
 [112; 113) 't': T
 [135; 261) '{     ....x() }': i128
-[146; 147) 'x': i32
-[150; 151) '1': i32
-[162; 163) 'y': i32
-[166; 168) 'id': fn id<i32>(T) -> T
-[166; 171) 'id(x)': i32
-[169; 170) 'x': i32
-[182; 183) 'a': A<i32>
-[186; 200) 'A { x: id(y) }': A<i32>
-[193; 195) 'id': fn id<i32>(T) -> T
-[193; 198) 'id(y)': i32
-[196; 197) 'y': i32
-[211; 212) 'z': i32
-[215; 217) 'id': fn id<i32>(T) -> T
-[215; 222) 'id(a.x)': i32
-[218; 219) 'a': A<i32>
-[218; 221) 'a.x': i32
-[233; 234) 'b': A<i32>
-[237; 247) 'A { x: z }': A<i32>
-[244; 245) 'z': i32
-[254; 255) 'b': A<i32>
+[146; 147) 'x': i128
+[150; 151) '1': i128
+[162; 163) 'y': i128
+[166; 168) 'id': fn id<i128>(T) -> T
+[166; 171) 'id(x)': i128
+[169; 170) 'x': i128
+[182; 183) 'a': A<i128>
+[186; 200) 'A { x: id(y) }': A<i128>
+[193; 195) 'id': fn id<i128>(T) -> T
+[193; 198) 'id(y)': i128
+[196; 197) 'y': i128
+[211; 212) 'z': i128
+[215; 217) 'id': fn id<i128>(T) -> T
+[215; 222) 'id(a.x)': i128
+[218; 219) 'a': A<i128>
+[218; 221) 'a.x': i128
+[233; 234) 'b': A<i128>
+[237; 247) 'A { x: z }': A<i128>
+[244; 245) 'z': i128
+[254; 255) 'b': A<i128>
 [254; 259) 'b.x()': i128
 
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics.snap
new file mode 100644
index 000000000..44f00a52e
--- /dev/null
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics.snap
@@ -0,0 +1,39 @@
+---
+created: "2019-02-16T21:58:14.029368845Z"
+creator: [email protected]
+source: crates/ra_hir/src/ty/tests.rs
+expression: "&result"
+---
+[74; 78) 'self': A<X, Y>
+[85; 107) '{     ...     }': X
+[95; 99) 'self': A<X, Y>
+[95; 101) 'self.x': X
+[117; 121) 'self': A<X, Y>
+[128; 150) '{     ...     }': Y
+[138; 142) 'self': A<X, Y>
+[138; 144) 'self.y': Y
+[163; 167) 'self': A<X, Y>
+[169; 170) 't': T
+[188; 223) '{     ...     }': (X, Y, T)
+[198; 217) '(self.....y, t)': (X, Y, T)
+[199; 203) 'self': A<X, Y>
+[199; 205) 'self.x': X
+[207; 211) 'self': A<X, Y>
+[207; 213) 'self.y': Y
+[215; 216) 't': T
+[245; 342) '{     ...(1); }': ()
+[255; 256) 'a': A<u64, i64>
+[259; 281) 'A { x:...1i64 }': A<u64, i64>
+[266; 270) '1u64': u64
+[275; 279) '1i64': i64
+[287; 288) 'a': A<u64, i64>
+[287; 292) 'a.x()': u64
+[298; 299) 'a': A<u64, i64>
+[298; 303) 'a.y()': i64
+[309; 310) 'a': A<u64, i64>
+[309; 319) 'a.z(1i128)': (u64, i64, i128)
+[313; 318) '1i128': i128
+[325; 326) 'a': A<u64, i64>
+[325; 339) 'a.z::<u128>(1)': (u64, i64, u128)
+[337; 338) '1': u128
+
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics_with_autoderef.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics_with_autoderef.snap
new file mode 100644
index 000000000..f609eaf7c
--- /dev/null
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_impl_generics_with_autoderef.snap
@@ -0,0 +1,16 @@
+---
+created: "2019-02-17T13:35:06.385679926Z"
+creator: [email protected]
+source: crates/ra_hir/src/ty/tests.rs
+expression: "&result"
+---
+[78; 82) 'self': &Option<T>
+[98; 100) '{}': ()
+[111; 112) 'o': Option<u32>
+[127; 165) '{     ...f(); }': ()
+[133; 146) '(&o).as_ref()': Option<&u32>
+[134; 136) '&o': &Option<u32>
+[135; 136) 'o': Option<u32>
+[152; 153) 'o': Option<u32>
+[152; 162) 'o.as_ref()': Option<&u32>
+