add __rvalue(expression) builtin (#17050)

compiler/test/runnable/rvalue1.d

@@ -0,0 +1,155 @@
+/* PERMUTE_ARGS: -preview=rvaluerefparam
+/* testing __rvalue */
+
+import core.stdc.stdio;
+
+/********************************/
+
+int foo(int) { printf("foo(int)\n"); return 1; }
+int foo(ref int) { printf("foo(ref int)\n"); return 2; }
+
+void test1()
+{
+    int s;
+    assert(foo(s) == 2);
+    assert(foo(__rvalue(s)) == 1);
+}
+
+/********************************/
+
+struct S
+{
+  nothrow:
+    ~this() { printf("~this() %p\n", &this); }
+    this(ref S) { printf("this(ref S)\n"); }
+    void opAssign(S) { printf("opAssign(S)\n"); }
+}
+
+void test2()
+{
+    S s;
+    S t;
+
+    t = __rvalue(s);
+}
+
+/********************************/
+
+struct S3
+{
+    int a, b, c;
+
+    this(S3) {}
+    this(ref S3) {}
+}
+
+void test3()
+{
+    S3 s;
+    S3 x = s; // this line causes the compiler to crash
+}
+
+/********************************/
+
+struct S4
+{
+    void* p;
+
+    this(S4 s)
+    {
+        assert(&s is &x); // confirm the rvalue reference
+    }
+}
+
+__gshared S4 x;
+
+void test4()
+{
+    S4 t = __rvalue(x);
+}
+
+/********************************/
+
+struct S5
+{
+    this(S5 s) { printf("this(S5 s)\n"); }
+    this(ref inout S5 s) inout { printf("this(ref inout S5 s) inout\n"); }
+}
+
+void test5()
+{
+    S5 t;
+    S5 t1 = t;
+    S5 t2 = __rvalue(t);
+}
+
+/********************************/
+
+int moveCtor, copyCtor, moveAss, copyAss;
+
+struct S6
+{
+    this(S6 s) { ++moveCtor; }
+    this(ref S6 s) { ++copyCtor; }
+    void opAssign(S6 s) { ++moveAss; }
+    void opAssign(ref S6 s) { ++copyAss; }
+}
+
+void test6()
+{
+    S6 x;
+    S6 s = x;
+//    printf("S6 s = x;            moveCtor %d copyCtor %d moveAss %d copyAss %d\n", moveCtor, copyCtor, moveAss, copyAss);
+    assert(copyCtor == 1);
+    S6 s2 = __rvalue(x);
+//    printf("S6 s2 = __rvalue(x); moveCtor %d copyCtor %d moveAss %d copyAss %d\n", moveCtor, copyCtor, moveAss, copyAss);
+    assert(moveCtor == 1);
+    s2 = s;
+//    printf("s2 = s;             moveCtor %d copyCtor %d moveAss %d copyAss %d\n", moveCtor, copyCtor, moveAss, copyAss);
+    assert(copyAss == 1);
+    s2 = __rvalue(s);
+//    printf("s2 = __rvalue(s);   moveCtor %d copyCtor %d moveAss %d copyAss %d\n", moveCtor, copyCtor, moveAss, copyAss);
+    assert(moveAss == 1);
+    assert(copyCtor == 1 && moveCtor == 1 && copyAss == 1 && moveAss == 1);
+}
+
+/********************************/
+// https://github.com/dlang/dmd/pull/17050#issuecomment-2543370370
+
+struct MutableString(size_t E) {}
+
+struct StringTest
+{
+    alias toString this;
+    const(char)[] toString() const pure
+        => null;
+
+    this(StringTest rhs) {}
+    this(ref inout StringTest rhs) inout pure {}
+
+    this(typeof(null)) inout pure {}
+    this(size_t Embed)(MutableString!Embed str) inout {}
+
+    ~this() {}
+}
+
+
+void test7()
+{
+    StringTest s = StringTest(null);
+}
+
+/********************************/
+
+int main()
+{
+    test1();
+    test2();
+    test3();
+    test4();
+    test5();
+    test6();
+    test7();
+
+    return 0;
+}

compiler/test/runnable/test23036.d

@@ -0,0 +1,13 @@
+// https://issues.dlang.org/show_bug.cgi?id=23036
+
+struct S
+{
+    this(ref S) {}
+    this(S, int a = 2) {}
+}
+
+void main()
+{
+    S a;
+    S b = a;
+}