Allow -> _ deduced return type for operator<=>, closes #571

hsutter · hsutter · commit 62dfdcb437d5 · 2023-08-12T17:03:02.000-10:00
This example now works: ``` quantity: @struct <Number: type> type = { number: Number; operator<=>: (this, that) -> _; } main: () = quantity<float>() < quantity<float>(); ```
diff --git a/regression-tests/test-results/version b/regression-tests/test-results/version
@@ -1,5 +1,5 @@
 
-cppfront compiler v0.2.1   Build 8812:1231
+cppfront compiler v0.2.1   Build 8812:1658
 Copyright(c) Herb Sutter   All rights reserved
 
 SPDX-License-Identifier: CC-BY-NC-ND-4.0
diff --git a/source/build.info b/source/build.info
@@ -1 +1 @@
-"8812:1231"
+"8812:1658"
diff --git a/source/sema.h b/source/sema.h
@@ -1392,8 +1392,9 @@ class sema
         if (n.has_name("operator<=>")) {
             auto return_name = n.unnamed_return_type_to_string();
             if (
-                return_name.find("strong_ordering") == return_name.npos
-                && return_name.find("weak_ordering") == return_name.npos
+                return_name != "_"
+                && return_name.find("strong_ordering" ) == return_name.npos
+                && return_name.find("weak_ordering"   ) == return_name.npos
                 && return_name.find("partial_ordering") == return_name.npos
                 )
             {

Original file line number	Diff line number	Diff line change
`@@ -1392,8 +1392,9 @@ class sema`
`1392`	`1392`	`if (n.has_name("operator<=>")) {`
`1393`	`1393`	`auto return_name = n.unnamed_return_type_to_string();`
`1394`	`1394`	`if (`
`1395`		`- return_name.find("strong_ordering") == return_name.npos`
`1396`		`- && return_name.find("weak_ordering") == return_name.npos`
	`1395`	`+ return_name != "_"`
	`1396`	`+ && return_name.find("strong_ordering" ) == return_name.npos`
	`1397`	`+ && return_name.find("weak_ordering" ) == return_name.npos`
`1397`	`1398`	`&& return_name.find("partial_ordering") == return_name.npos`
`1398`	`1399`	`)`
`1399`	`1400`	`{`