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authorbors[bot] <26634292+bors[bot]@users.noreply.github.com>2020-10-15 19:02:27 +0100
committerGitHub <[email protected]>2020-10-15 19:02:27 +0100
commit0d45802d671f94cb768b93a64882733396cfbe2d (patch)
treeabb91645ee84216304065bf42a959223d040814c /crates/hir_ty/src/tests
parent1de202010948c94658235f7cfe9b25dda0c7ddf3 (diff)
parent0e9d1e17d6e45b44ec1a8f1430109cfc75e41241 (diff)
Merge #6220
6220: implement binary operator overloading type inference r=flodiebold a=ruabmbua Extend type inference of *binary operator expression*, by adding support for operator overloads. Before this merge request, the type inference of binary expressions could only resolve operations done on built-in primitive types. This merge requests adds a code path, which is executed in case the built-in inference could not get any results. It resolves the proper operator overload trait in *core::ops* via lang items, and then resolves the associated *Output* type. ```rust struct V2([f32; 2]); #[lang = "add"] pub trait Add<Rhs = Self> { /// The resulting type after applying the `+` operator. type Output; /// Performs the `+` operation. #[must_use] fn add(self, rhs: Rhs) -> Self::Output; } impl Add<V2> for V2 { type Output = V2; fn add(self, rhs: V2) -> V2 { let x = self.0[0] + rhs.0[0]; let y = self.0[1] + rhs.0[1]; V2([x, y]) } } fn test() { let va = V2([0.0, 1.0]); let vb = V2([0.0, 1.0]); let r = va + vb; // This infers to V2 now } ``` There is a problem with operator overloads, which do not explicitly set the *Rhs* type parameter in the respective impl block. **Example:** ```rust impl Add for V2 { type Output = V2; fn add(self, rhs: V2) -> V2 { let x = self.0[0] + rhs.0[0]; let y = self.0[1] + rhs.0[1]; V2([x, y]) } } ``` In this case, the trait solver does not realize, that the *Rhs* type parameter is actually self in the context of the impl block. This stops type inference in its tracks, and it can not resolve the associated *Output* type. I guess we can still merge this back, because it increases the amount of resolved types, and does not regress anything (in the tests). Somewhat blocked by https://github.com/rust-analyzer/rust-analyzer/issues/5685 Resolves https://github.com/rust-analyzer/rust-analyzer/issues/5544 Co-authored-by: Roland Ruckerbauer <[email protected]>
Diffstat (limited to 'crates/hir_ty/src/tests')
-rw-r--r--crates/hir_ty/src/tests/simple.rs89
1 files changed, 89 insertions, 0 deletions
diff --git a/crates/hir_ty/src/tests/simple.rs b/crates/hir_ty/src/tests/simple.rs
index 5b07948f3..4f72582b6 100644
--- a/crates/hir_ty/src/tests/simple.rs
+++ b/crates/hir_ty/src/tests/simple.rs
@@ -1,4 +1,5 @@
1use expect_test::expect; 1use expect_test::expect;
2use test_utils::mark;
2 3
3use super::{check_infer, check_types}; 4use super::{check_infer, check_types};
4 5
@@ -2225,3 +2226,91 @@ fn generic_default_depending_on_other_type_arg_forward() {
2225 "#]], 2226 "#]],
2226 ); 2227 );
2227} 2228}
2229
2230#[test]
2231fn infer_operator_overload() {
2232 mark::check!(infer_expr_inner_binary_operator_overload);
2233
2234 check_infer(
2235 r#"
2236 struct V2([f32; 2]);
2237
2238 #[lang = "add"]
2239 pub trait Add<Rhs = Self> {
2240 /// The resulting type after applying the `+` operator.
2241 type Output;
2242
2243 /// Performs the `+` operation.
2244 #[must_use]
2245 fn add(self, rhs: Rhs) -> Self::Output;
2246 }
2247
2248 impl Add<V2> for V2 {
2249 type Output = V2;
2250
2251 fn add(self, rhs: V2) -> V2 {
2252 let x = self.0[0] + rhs.0[0];
2253 let y = self.0[1] + rhs.0[1];
2254 V2([x, y])
2255 }
2256 }
2257
2258 fn test() {
2259 let va = V2([0.0, 1.0]);
2260 let vb = V2([0.0, 1.0]);
2261
2262 let r = va + vb;
2263 }
2264
2265 "#,
2266 expect![[r#"
2267 207..211 'self': Self
2268 213..216 'rhs': Rhs
2269 299..303 'self': V2
2270 305..308 'rhs': V2
2271 320..422 '{ ... }': V2
2272 334..335 'x': f32
2273 338..342 'self': V2
2274 338..344 'self.0': [f32; _]
2275 338..347 'self.0[0]': {unknown}
2276 338..358 'self.0...s.0[0]': f32
2277 345..346 '0': i32
2278 350..353 'rhs': V2
2279 350..355 'rhs.0': [f32; _]
2280 350..358 'rhs.0[0]': {unknown}
2281 356..357 '0': i32
2282 372..373 'y': f32
2283 376..380 'self': V2
2284 376..382 'self.0': [f32; _]
2285 376..385 'self.0[1]': {unknown}
2286 376..396 'self.0...s.0[1]': f32
2287 383..384 '1': i32
2288 388..391 'rhs': V2
2289 388..393 'rhs.0': [f32; _]
2290 388..396 'rhs.0[1]': {unknown}
2291 394..395 '1': i32
2292 406..408 'V2': V2([f32; _]) -> V2
2293 406..416 'V2([x, y])': V2
2294 409..415 '[x, y]': [f32; _]
2295 410..411 'x': f32
2296 413..414 'y': f32
2297 436..519 '{ ... vb; }': ()
2298 446..448 'va': V2
2299 451..453 'V2': V2([f32; _]) -> V2
2300 451..465 'V2([0.0, 1.0])': V2
2301 454..464 '[0.0, 1.0]': [f32; _]
2302 455..458 '0.0': f32
2303 460..463 '1.0': f32
2304 475..477 'vb': V2
2305 480..482 'V2': V2([f32; _]) -> V2
2306 480..494 'V2([0.0, 1.0])': V2
2307 483..493 '[0.0, 1.0]': [f32; _]
2308 484..487 '0.0': f32
2309 489..492 '1.0': f32
2310 505..506 'r': V2
2311 509..511 'va': V2
2312 509..516 'va + vb': V2
2313 514..516 'vb': V2
2314 "#]],
2315 );
2316}