FuncDeclaration *hasIdentityOpAssign(AggregateDeclaration *ad, Scope *sc)
{
Dsymbol *assign = search_function(ad, Id::assign);
if (assign)
{
/* check identity opAssign exists
*/
Expression *er = new NullExp(ad->loc, ad->type); // dummy rvalue
Expression *el = new IdentifierExp(ad->loc, Id::p); // dummy lvalue
el->type = ad->type;
Expressions *a = new Expressions();
a->setDim(1);
FuncDeclaration *f = NULL;
unsigned errors = global.startGagging(); // Do not report errors, even if the
unsigned oldspec = global.speculativeGag; // template opAssign fbody makes it.
global.speculativeGag = global.gag;
sc = sc->push();
sc->speculative = true;
for (size_t i = 0; i < 2; i++)
{
(*a)[0] = (i == 0 ? er : el);
f = resolveFuncCall(ad->loc, sc, assign, NULL, ad->type, a, 1);
if (f)
break;
}
sc = sc->pop();
global.speculativeGag = oldspec;
global.endGagging(errors);
if (f)
{
if (f->errors)
return NULL;
int varargs;
Parameters *fparams = f->getParameters(&varargs);
if (fparams->dim >= 1)
{
Parameter *arg0 = Parameter::getNth(fparams, 0);
if (arg0->type->toDsymbol(NULL) != ad)
f = NULL;
}
}
// BUGS: This detection mechanism cannot find some opAssign-s like follows:
// struct S { void opAssign(ref immutable S) const; }
return f;
}
return NULL;
}
FuncDeclaration *AggregateDeclaration::hasIdentityOpAssign(Scope *sc, Dsymbol *assign)
{
if (assign)
{
/* check identity opAssign exists
*/
Expression *er = new NullExp(loc, type); // dummy rvalue
Expression *el = new IdentifierExp(loc, Id::p); // dummy lvalue
el->type = type;
Expressions ar; ar.push(er);
Expressions al; al.push(el);
FuncDeclaration *f = NULL;
unsigned errors = global.startGagging(); // Do not report errors, even if the
unsigned oldspec = global.speculativeGag; // template opAssign fbody makes it.
global.speculativeGag = global.gag;
sc = sc->push();
sc->speculative = true;
f = resolveFuncCall(loc, sc, assign, NULL, er, &ar, 1);
if (!f) f = resolveFuncCall(loc, sc, assign, NULL, er, &al, 1);
sc = sc->pop();
global.speculativeGag = oldspec;
global.endGagging(errors);
if (f)
{
int varargs;
Parameters *fparams = f->getParameters(&varargs);
if (fparams->dim >= 1)
{
Parameter *arg0 = Parameter::getNth(fparams, 0);
if (arg0->type->toDsymbol(NULL) != this)
f = NULL;
}
}
// BUGS: This detection mechanism cannot find some opAssign-s like follows:
// struct S { void opAssign(ref immutable S) const; }
return f;
}
return NULL;
}
