fix Issue 13484 - Template type deduction from delegate parameter fails

The implicit conversion of expressions to delegates was added in 0.165 (a2b1fa4, http://www.digitalmars.com/d/1.0/changelog2.html#new0165), but it was replaced with lazy parameter.
dlang · Sep 17, 2014 · bfa9a00 · bfa9a00
1 parent 9bbe770
commit bfa9a00
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Showing 2 changed files with 27 additions and 33 deletions.
diff --git a/src/template.c b/src/template.c
@@ -1568,39 +1568,20 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(
             if (m == MATCHnomatch && prmtype->deco)
                 m = farg->implicitConvTo(prmtype);
 
-            /* If no match, see if there's a conversion to a delegate
-             */
             if (m == MATCHnomatch)
             {
-                Type *tbp = prmtype->toBasetype();
-                Type *tba = farg->type->toBasetype();
-                if (tbp->ty == Tdelegate)
-                {
-                    TypeDelegate *td = (TypeDelegate *)prmtype->toBasetype();
-                    TypeFunction *tf = (TypeFunction *)td->next;
-
-                    if (!tf->varargs && Parameter::dim(tf->parameters) == 0)
-                    {
-                        m = deduceType(farg->type, paramscope, tf->next, parameters, dedtypes);
-                        if (m == MATCHnomatch && tf->next->toBasetype()->ty == Tvoid)
-                            m = MATCHconvert;
-                    }
-                    //printf("\tm2 = %d\n", m);
-                }
-                else if (AggregateDeclaration *ad = isAggregate(tba))
+                AggregateDeclaration *ad = isAggregate(farg->type);
+                if (ad && ad->aliasthis)
                 {
-                    if (ad->aliasthis)
+                    /* If a semantic error occurs while doing alias this,
+                     * eg purity(bug 7295), just regard it as not a match.
+                     */
+                    unsigned olderrors = global.startGagging();
+                    Expression *e = resolveAliasThis(sc, farg);
+                    if (!global.endGagging(olderrors))
                     {
-                        /* If a semantic error occurs while doing alias this,
-                         * eg purity(bug 7295), just regard it as not a match.
-                         */
-                        unsigned olderrors = global.startGagging();
-                        Expression *e = resolveAliasThis(sc, farg);
-                        if (!global.endGagging(olderrors))
-                        {
-                            farg = e;
-                            goto Lretry;
-                        }
+                        farg = e;
+                        goto Lretry;
                     }
                 }
             }
@@ -1872,10 +1853,10 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(
     }
 
 #if 0
-    for (i = 0; i < dedargs->dim; i++)
+    for (size_t i = 0; i < dedargs->dim; i++)
     {
-        Type *t = (*dedargs)[i];
-        printf("\tdedargs[%d] = %d, %s\n", i, t->dyncast(), t->toChars());
+        RootObject *o = (*dedargs)[i];
+        printf("\tdedargs[%d] = %d, %s\n", i, o->dyncast(), o->toChars());
     }
 #endif
 
@@ -3513,7 +3494,7 @@ MATCH deduceType(RootObject *o, Scope *sc, Type *tparam, TemplateParameters *par
                     fparam->type = fparam->type->addStorageClass(fparam->storageClass);
                     fparam->storageClass &= ~(STC_TYPECTOR | STCin);
                 }
-                //printf("\t-> this   = %d, ", ty); print();
+                //printf("\t-> this   = %d, ", t->ty); t->print();
                 //printf("\t-> tparam = %d, ", tparam->ty); tparam->print();
 
                 /* See if tuple match

diff --git a/test/runnable/template9.d b/test/runnable/template9.d
@@ -4216,6 +4216,18 @@ void test13417()
     f13417(V13417!(4, float, "ijka")());
 }
 
+/******************************************/
+// 13484
+
+int foo13484()(void delegate() hi) { return 1; }
+int foo13484(T)(void delegate(T) hi) { return 2; }
+
+void test13484()
+{
+    assert(foo13484({}) == 1);          // works
+    assert(foo13484((float v){}) == 2); // works <- throws error
+}
+
 /******************************************/
 
 int main()
@@ -4321,6 +4333,7 @@ int main()
     test13374();
     test13378();
     test13379();
+    test13484();
 
     printf("Success\n");
     return 0;