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cast.c
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cast.c
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// Copyright (c) 1999-2011 by Digital Mars
// All Rights Reserved
// written by Walter Bright
// http://www.digitalmars.com
// License for redistribution is by either the Artistic License
// in artistic.txt, or the GNU General Public License in gnu.txt.
// See the included readme.txt for details.
#include <stdio.h>
#include <assert.h>
#include "rmem.h"
#include "expression.h"
#include "mtype.h"
#include "utf.h"
#include "declaration.h"
#include "aggregate.h"
#include "scope.h"
//#define DUMP .dump(__PRETTY_FUNCTION__, this)
#define DUMP
/* ==================== implicitCast ====================== */
/**************************************
* Do an implicit cast.
* Issue error if it can't be done.
*/
Expression *Expression::implicitCastTo(Scope *sc, Type *t)
{
//printf("Expression::implicitCastTo(%s of type %s) => %s\n", toChars(), type->toChars(), t->toChars());
MATCH match = implicitConvTo(t);
if (match)
{ TY tyfrom = type->toBasetype()->ty;
TY tyto = t->toBasetype()->ty;
#if DMDV1
if (global.params.warnings &&
Type::impcnvWarn[tyfrom][tyto] &&
op != TOKint64)
{
Expression *e = optimize(WANTflags | WANTvalue);
if (e->op == TOKint64)
return e->implicitCastTo(sc, t);
if (tyfrom == Tint32 &&
(op == TOKadd || op == TOKmin ||
op == TOKand || op == TOKor || op == TOKxor)
)
{
/* This is really only a semi-kludge fix,
* we really should look at the operands of op
* and see if they are narrower types.
* For example, b=b|b and b=b|7 and s=b+b should be allowed,
* but b=b|i should be an error.
*/
;
}
else
{
warning("implicit conversion of expression (%s) of type %s to %s can cause loss of data",
toChars(), type->toChars(), t->toChars());
}
}
#endif
#if DMDV2
if (match == MATCHconst && t == type->constOf())
{
Expression *e = copy();
e->type = t;
return e;
}
#endif
return castTo(sc, t);
}
Expression *e = optimize(WANTflags | WANTvalue);
if (e != this)
return e->implicitCastTo(sc, t);
#if 0
printf("ty = %d\n", type->ty);
print();
type->print();
printf("to:\n");
t->print();
printf("%p %p type: %s to: %s\n", type->deco, t->deco, type->deco, t->deco);
//printf("%p %p %p\n", type->nextOf()->arrayOf(), type, t);
fflush(stdout);
#endif
if (t->ty != Terror && type->ty != Terror)
{
if (!t->deco)
{ /* Can happen with:
* enum E { One }
* class A
* { static void fork(EDG dg) { dg(E.One); }
* alias void delegate(E) EDG;
* }
* Should eventually make it work.
*/
error("forward reference to type %s", t->toChars());
}
else if (t->reliesOnTident())
error("forward reference to type %s", t->reliesOnTident()->toChars());
error("cannot implicitly convert expression (%s) of type %s to %s",
toChars(), type->toChars(), t->toChars());
}
return new ErrorExp();
}
Expression *StringExp::implicitCastTo(Scope *sc, Type *t)
{
//printf("StringExp::implicitCastTo(%s of type %s) => %s\n", toChars(), type->toChars(), t->toChars());
unsigned char committed = this->committed;
Expression *e = Expression::implicitCastTo(sc, t);
if (e->op == TOKstring)
{
// Retain polysemous nature if it started out that way
((StringExp *)e)->committed = committed;
}
return e;
}
Expression *ErrorExp::implicitCastTo(Scope *sc, Type *t)
{
return this;
}
/*******************************************
* Return !=0 if we can implicitly convert this to type t.
* Don't do the actual cast.
*/
MATCH Expression::implicitConvTo(Type *t)
{
#if 0
printf("Expression::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
//static int nest; if (++nest == 10) halt();
if (t == Type::terror)
return MATCHnomatch;
if (!type)
{ error("%s is not an expression", toChars());
type = Type::terror;
}
Expression *e = optimize(WANTvalue | WANTflags);
if (e->type == t)
return MATCHexact;
if (e != this)
{ //printf("\toptimized to %s of type %s\n", e->toChars(), e->type->toChars());
return e->implicitConvTo(t);
}
MATCH match = type->implicitConvTo(t);
if (match != MATCHnomatch)
return match;
/* See if we can do integral narrowing conversions
*/
if (type->isintegral() && t->isintegral() &&
type->isTypeBasic() && t->isTypeBasic())
{ IntRange src = this->getIntRange() DUMP;
IntRange targetUnsigned = IntRange::fromType(t, /*isUnsigned*/true) DUMP;
IntRange targetSigned = IntRange::fromType(t, /*isUnsigned*/false) DUMP;
if (targetUnsigned.contains(src) || targetSigned.contains(src))
return MATCHconvert;
}
#if 0
Type *tb = t->toBasetype();
if (tb->ty == Tdelegate)
{ TypeDelegate *td = (TypeDelegate *)tb;
TypeFunction *tf = (TypeFunction *)td->nextOf();
if (!tf->varargs &&
!(tf->arguments && tf->arguments->dim)
)
{
match = type->implicitConvTo(tf->nextOf());
if (match)
return match;
if (tf->nextOf()->toBasetype()->ty == Tvoid)
return MATCHconvert;
}
}
#endif
return MATCHnomatch;
}
MATCH IntegerExp::implicitConvTo(Type *t)
{
#if 0
printf("IntegerExp::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
MATCH m = type->implicitConvTo(t);
if (m >= MATCHconst)
return m;
TY ty = type->toBasetype()->ty;
TY toty = t->toBasetype()->ty;
if (m == MATCHnomatch && t->ty == Tenum)
goto Lno;
if (t->ty == Tvector)
{ TypeVector *tv = (TypeVector *)t;
TypeBasic *tb = tv->elementType();
toty = tb->ty;
}
switch (ty)
{
case Tbool:
value &= 1;
ty = Tint32;
break;
case Tint8:
value = (signed char)value;
ty = Tint32;
break;
case Tchar:
case Tuns8:
value &= 0xFF;
ty = Tint32;
break;
case Tint16:
value = (short)value;
ty = Tint32;
break;
case Tuns16:
case Twchar:
value &= 0xFFFF;
ty = Tint32;
break;
case Tint32:
value = (int)value;
break;
case Tuns32:
case Tdchar:
value &= 0xFFFFFFFF;
ty = Tuns32;
break;
default:
break;
}
// Only allow conversion if no change in value
switch (toty)
{
case Tbool:
if ((value & 1) != value)
goto Lno;
goto Lyes;
case Tint8:
if ((signed char)value != value)
goto Lno;
goto Lyes;
case Tchar:
case Tuns8:
//printf("value = %llu %llu\n", (dinteger_t)(unsigned char)value, value);
if ((unsigned char)value != value)
goto Lno;
goto Lyes;
case Tint16:
if ((short)value != value)
goto Lno;
goto Lyes;
case Tuns16:
if ((unsigned short)value != value)
goto Lno;
goto Lyes;
case Tint32:
if (ty == Tuns32)
{
}
else if ((int)value != value)
goto Lno;
goto Lyes;
case Tuns32:
if (ty == Tint32)
{
}
else if ((unsigned)value != value)
goto Lno;
goto Lyes;
case Tdchar:
if (value > 0x10FFFFUL)
goto Lno;
goto Lyes;
case Twchar:
if ((unsigned short)value != value)
goto Lno;
goto Lyes;
case Tfloat32:
{
volatile float f;
if (type->isunsigned())
{
f = (float)value;
if (f != value)
goto Lno;
}
else
{
f = (float)(long long)value;
if (f != (long long)value)
goto Lno;
}
goto Lyes;
}
case Tfloat64:
{
volatile double f;
if (type->isunsigned())
{
f = (double)value;
if (f != value)
goto Lno;
}
else
{
f = (double)(long long)value;
if (f != (long long)value)
goto Lno;
}
goto Lyes;
}
case Tfloat80:
{
volatile long double f;
if (type->isunsigned())
{
f = (long double)value;
if (f != value)
goto Lno;
}
else
{
f = (long double)(long long)value;
if (f != (long long)value)
goto Lno;
}
goto Lyes;
}
case Tpointer:
//printf("type = %s\n", type->toBasetype()->toChars());
//printf("t = %s\n", t->toBasetype()->toChars());
if (ty == Tpointer &&
type->toBasetype()->nextOf()->ty == t->toBasetype()->nextOf()->ty)
{ /* Allow things like:
* const char* P = cast(char *)3;
* char* q = P;
*/
goto Lyes;
}
break;
}
return Expression::implicitConvTo(t);
Lyes:
//printf("MATCHconvert\n");
return MATCHconvert;
Lno:
//printf("MATCHnomatch\n");
return MATCHnomatch;
}
MATCH NullExp::implicitConvTo(Type *t)
{
#if 0
printf("NullExp::implicitConvTo(this=%s, type=%s, t=%s, committed = %d)\n",
toChars(), type->toChars(), t->toChars(), committed);
#endif
if (this->type->equals(t))
return MATCHexact;
/* Allow implicit conversions from immutable to mutable|const,
* and mutable to immutable. It works because, after all, a null
* doesn't actually point to anything.
*/
if (t->invariantOf()->equals(type->invariantOf()))
return MATCHconst;
return Expression::implicitConvTo(t);
}
#if DMDV2
MATCH StructLiteralExp::implicitConvTo(Type *t)
{
#if 0
printf("StructLiteralExp::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
MATCH m = Expression::implicitConvTo(t);
if (m != MATCHnomatch)
return m;
if (type->ty == t->ty && type->ty == Tstruct &&
((TypeStruct *)type)->sym == ((TypeStruct *)t)->sym)
{
m = MATCHconst;
for (size_t i = 0; i < elements->dim; i++)
{ Expression *e = (*elements)[i];
Type *te = e->type;
te = te->castMod(t->mod);
MATCH m2 = e->implicitConvTo(te);
//printf("\t%s => %s, match = %d\n", e->toChars(), te->toChars(), m2);
if (m2 < m)
m = m2;
}
}
return m;
}
#endif
MATCH StringExp::implicitConvTo(Type *t)
{
#if 0
printf("StringExp::implicitConvTo(this=%s, committed=%d, type=%s, t=%s)\n",
toChars(), committed, type->toChars(), t->toChars());
#endif
if (!committed && t->ty == Tpointer && t->nextOf()->ty == Tvoid)
{
return MATCHnomatch;
}
if (type->ty == Tsarray || type->ty == Tarray || type->ty == Tpointer)
{
TY tyn = type->nextOf()->ty;
if (tyn == Tchar || tyn == Twchar || tyn == Tdchar)
{ Type *tn;
MATCH m;
switch (t->ty)
{
case Tsarray:
if (type->ty == Tsarray)
{
if (((TypeSArray *)type)->dim->toInteger() !=
((TypeSArray *)t)->dim->toInteger())
return MATCHnomatch;
TY tynto = t->nextOf()->ty;
if (tynto == tyn)
return MATCHexact;
if (!committed && (tynto == Tchar || tynto == Twchar || tynto == Tdchar))
return MATCHexact;
}
else if (type->ty == Tarray)
{
if (length() >
((TypeSArray *)t)->dim->toInteger())
return MATCHnomatch;
TY tynto = t->nextOf()->ty;
if (tynto == tyn)
return MATCHexact;
if (!committed && (tynto == Tchar || tynto == Twchar || tynto == Tdchar))
return MATCHexact;
}
case Tarray:
case Tpointer:
tn = t->nextOf();
m = MATCHexact;
if (type->nextOf()->mod != tn->mod)
{ if (!tn->isConst())
return MATCHnomatch;
m = MATCHconst;
}
switch (tn->ty)
{
case Tchar:
case Twchar:
case Tdchar:
if (!committed)
return m;
break;
}
break;
}
}
}
return Expression::implicitConvTo(t);
#if 0
m = (MATCH)type->implicitConvTo(t);
if (m)
{
return m;
}
return MATCHnomatch;
#endif
}
MATCH ArrayLiteralExp::implicitConvTo(Type *t)
{ MATCH result = MATCHexact;
#if 0
printf("ArrayLiteralExp::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
Type *typeb = type->toBasetype();
Type *tb = t->toBasetype();
if ((tb->ty == Tarray || tb->ty == Tsarray) &&
(typeb->ty == Tarray || typeb->ty == Tsarray))
{
if (tb->ty == Tsarray)
{ TypeSArray *tsa = (TypeSArray *)tb;
if (elements->dim != tsa->dim->toInteger())
result = MATCHnomatch;
}
for (size_t i = 0; i < elements->dim; i++)
{ Expression *e = (*elements)[i];
MATCH m = (MATCH)e->implicitConvTo(tb->nextOf());
if (m < result)
result = m; // remember worst match
if (result == MATCHnomatch)
break; // no need to check for worse
}
if (!result)
result = type->implicitConvTo(t);
return result;
}
else
return Expression::implicitConvTo(t);
}
MATCH AssocArrayLiteralExp::implicitConvTo(Type *t)
{ MATCH result = MATCHexact;
Type *typeb = type->toBasetype();
Type *tb = t->toBasetype();
if (tb->ty == Taarray && typeb->ty == Taarray)
{
for (size_t i = 0; i < keys->dim; i++)
{ Expression *e = keys->tdata()[i];
MATCH m = (MATCH)e->implicitConvTo(((TypeAArray *)tb)->index);
if (m < result)
result = m; // remember worst match
if (result == MATCHnomatch)
break; // no need to check for worse
e = values->tdata()[i];
m = (MATCH)e->implicitConvTo(tb->nextOf());
if (m < result)
result = m; // remember worst match
if (result == MATCHnomatch)
break; // no need to check for worse
}
return result;
}
else
return Expression::implicitConvTo(t);
}
MATCH CallExp::implicitConvTo(Type *t)
{
#if 0
printf("CalLExp::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
MATCH m = Expression::implicitConvTo(t);
if (m)
return m;
/* Allow the result of strongly pure functions to
* convert to immutable
*/
if (f && f->isPure() == PUREstrong && !f->type->hasWild())
return type->invariantOf()->implicitConvTo(t);
return MATCHnomatch;
}
MATCH AddrExp::implicitConvTo(Type *t)
{
#if 0
printf("AddrExp::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
MATCH result;
result = type->implicitConvTo(t);
//printf("\tresult = %d\n", result);
if (result == MATCHnomatch)
{
// Look for pointers to functions where the functions are overloaded.
t = t->toBasetype();
if (e1->op == TOKoverloadset &&
(t->ty == Tpointer || t->ty == Tdelegate) && t->nextOf()->ty == Tfunction)
{ OverExp *eo = (OverExp *)e1;
FuncDeclaration *f = NULL;
for (size_t i = 0; i < eo->vars->a.dim; i++)
{ Dsymbol *s = eo->vars->a[i];
FuncDeclaration *f2 = s->isFuncDeclaration();
assert(f2);
if (f2->overloadExactMatch(t->nextOf()))
{ if (f)
/* Error if match in more than one overload set,
* even if one is a 'better' match than the other.
*/
ScopeDsymbol::multiplyDefined(loc, f, f2);
else
f = f2;
result = MATCHexact;
}
}
}
if (type->ty == Tpointer && type->nextOf()->ty == Tfunction &&
t->ty == Tpointer && t->nextOf()->ty == Tfunction &&
e1->op == TOKvar)
{
/* I don't think this can ever happen -
* it should have been
* converted to a SymOffExp.
*/
assert(0);
VarExp *ve = (VarExp *)e1;
FuncDeclaration *f = ve->var->isFuncDeclaration();
if (f && f->overloadExactMatch(t->nextOf()))
result = MATCHexact;
}
}
//printf("\tresult = %d\n", result);
return result;
}
MATCH SymOffExp::implicitConvTo(Type *t)
{
#if 0
printf("SymOffExp::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
MATCH result;
result = type->implicitConvTo(t);
//printf("\tresult = %d\n", result);
if (result == MATCHnomatch)
{
// Look for pointers to functions where the functions are overloaded.
FuncDeclaration *f;
t = t->toBasetype();
if (type->ty == Tpointer && type->nextOf()->ty == Tfunction &&
(t->ty == Tpointer || t->ty == Tdelegate) && t->nextOf()->ty == Tfunction)
{
f = var->isFuncDeclaration();
if (f)
{ f = f->overloadExactMatch(t->nextOf());
if (f)
{ if ((t->ty == Tdelegate && (f->needThis() || f->isNested())) ||
(t->ty == Tpointer && !(f->needThis() || f->isNested())))
{
result = MATCHexact;
}
}
}
}
}
//printf("\tresult = %d\n", result);
return result;
}
MATCH DelegateExp::implicitConvTo(Type *t)
{
#if 0
printf("DelegateExp::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
MATCH result;
result = type->implicitConvTo(t);
if (result == MATCHnomatch)
{
// Look for pointers to functions where the functions are overloaded.
t = t->toBasetype();
if (type->ty == Tdelegate &&
t->ty == Tdelegate)
{
if (func && func->overloadExactMatch(t->nextOf()))
result = MATCHexact;
}
}
return result;
}
MATCH FuncExp::implicitConvTo(Type *t)
{
//printf("FuncExp::implicitCastTo type = %p %s, t = %s\n", type, type ? type->toChars() : NULL, t->toChars());
if (type && type != Type::tvoid && tok == TOKreserved && type->ty == Tpointer
&& (t->ty == Tpointer || t->ty == Tdelegate))
{ // Allow implicit function to delegate conversion
if (type->nextOf()->covariant(t->nextOf()) == 1)
return t->ty == Tpointer ? MATCHconst : MATCHconvert;
}
return Expression::implicitConvTo(t);
}
MATCH OrExp::implicitConvTo(Type *t)
{
MATCH result = Expression::implicitConvTo(t);
if (result == MATCHnomatch)
{
MATCH m1 = e1->implicitConvTo(t);
MATCH m2 = e2->implicitConvTo(t);
// Pick the worst match
result = (m1 < m2) ? m1 : m2;
}
return result;
}
MATCH XorExp::implicitConvTo(Type *t)
{
MATCH result = Expression::implicitConvTo(t);
if (result == MATCHnomatch)
{
MATCH m1 = e1->implicitConvTo(t);
MATCH m2 = e2->implicitConvTo(t);
// Pick the worst match
result = (m1 < m2) ? m1 : m2;
}
return result;
}
MATCH CondExp::implicitConvTo(Type *t)
{
MATCH m1 = e1->implicitConvTo(t);
MATCH m2 = e2->implicitConvTo(t);
//printf("CondExp: m1 %d m2 %d\n", m1, m2);
// Pick the worst match
return (m1 < m2) ? m1 : m2;
}
MATCH CommaExp::implicitConvTo(Type *t)
{
return e2->implicitConvTo(t);
}
MATCH CastExp::implicitConvTo(Type *t)
{
#if 0
printf("CastExp::implicitConvTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
MATCH result;
result = type->implicitConvTo(t);
if (result == MATCHnomatch)
{
if (t->isintegral() &&
e1->type->isintegral() &&
e1->implicitConvTo(t) != MATCHnomatch)
result = MATCHconvert;
else
result = Expression::implicitConvTo(t);
}
return result;
}
/* ==================== castTo ====================== */
/**************************************
* Do an explicit cast.
*/
Expression *Expression::castTo(Scope *sc, Type *t)
{
//printf("Expression::castTo(this=%s, t=%s)\n", toChars(), t->toChars());
#if 0
printf("Expression::castTo(this=%s, type=%s, t=%s)\n",
toChars(), type->toChars(), t->toChars());
#endif
if (type == t)
return this;
Expression *e = this;
Type *tb = t->toBasetype();
Type *typeb = type->toBasetype();
if (tb != typeb)
{
// Do (type *) cast of (type [dim])
if (tb->ty == Tpointer &&
typeb->ty == Tsarray
)
{
//printf("Converting [dim] to *\n");
if (typeb->size(loc) == 0)
e = new NullExp(loc);
else
e = new AddrExp(loc, e);
}
#if 0
else if (tb->ty == Tdelegate && type->ty != Tdelegate)
{
TypeDelegate *td = (TypeDelegate *)tb;
TypeFunction *tf = (TypeFunction *)td->nextOf();
return toDelegate(sc, tf->nextOf());
}
#endif
else
{
if (typeb->ty == Tstruct)
{ TypeStruct *ts = (TypeStruct *)typeb;
if (!(tb->ty == Tstruct && ts->sym == ((TypeStruct *)tb)->sym) &&
ts->sym->aliasthis)
{ /* Forward the cast to our alias this member, rewrite to:
* cast(to)e1.aliasthis
*/
Expression *e1 = new DotIdExp(loc, this, ts->sym->aliasthis->ident);
Expression *e2 = new CastExp(loc, e1, tb);
e2 = e2->semantic(sc);
return e2;
}
}
else if (typeb->ty == Tclass)
{ TypeClass *ts = (TypeClass *)typeb;
if (ts->sym->aliasthis)
{
if (tb->ty == Tclass)
{
ClassDeclaration *cdfrom = typeb->isClassHandle();
ClassDeclaration *cdto = tb->isClassHandle();
int offset;
if (cdto->isBaseOf(cdfrom, &offset))
goto L1;
}
/* Forward the cast to our alias this member, rewrite to:
* cast(to)e1.aliasthis
*/
Expression *e1 = new DotIdExp(loc, this, ts->sym->aliasthis->ident);
Expression *e2 = new CastExp(loc, e1, tb);
e2 = e2->semantic(sc);
return e2;
}
L1: ;
}
else if (tb->ty == Tvector && typeb->ty != Tvector)
{
e = new VectorExp(loc, e, tb);
e = e->semantic(sc);
return e;
}
e = new CastExp(loc, e, tb);
}
}
else
{
e = e->copy(); // because of COW for assignment to e->type
}
assert(e != this);
e->type = t;
//printf("Returning: %s\n", e->toChars());
return e;
}
Expression *ErrorExp::castTo(Scope *sc, Type *t)
{
return this;
}
Expression *RealExp::castTo(Scope *sc, Type *t)
{ Expression *e = this;
if (type != t)
{
if ((type->isreal() && t->isreal()) ||
(type->isimaginary() && t->isimaginary())
)
{ e = copy();
e->type = t;
}
else
e = Expression::castTo(sc, t);
}
return e;
}
Expression *ComplexExp::castTo(Scope *sc, Type *t)
{ Expression *e = this;
if (type != t)
{
if (type->iscomplex() && t->iscomplex())
{ e = copy();
e->type = t;
}
else
e = Expression::castTo(sc, t);
}
return e;
}
Expression *NullExp::castTo(Scope *sc, Type *t)
{
//printf("NullExp::castTo(t = %p)\n", t);
if (type == t)
{
committed = 1;
return this;
}
NullExp *e = (NullExp *)copy();
e->committed = 1;
Type *tb = t->toBasetype();
#if 0
e->type = type->toBasetype();
if (tb != e->type)
{
// NULL implicitly converts to any pointer type or dynamic array
if (e->type->ty == Tpointer && e->type->nextOf()->ty == Tvoid &&
(tb->ty == Tpointer || tb->ty == Tarray || tb->ty == Taarray ||
tb->ty == Tdelegate))
{
if (tb->ty == Tdelegate)
{ TypeDelegate *td = (TypeDelegate *)tb;
TypeFunction *tf = (TypeFunction *)td->nextOf();
if (!tf->varargs &&
!(tf->arguments && tf->arguments->dim)
)
{
return Expression::castTo(sc, t);
}
}
}
else
{
//return e->Expression::castTo(sc, t);
}
}
#else
if (tb->ty == Tvoid)
{
e->type = type->toBasetype();
return e->Expression::castTo(sc, t);
}
#endif
e->type = t;
return e;
}
Expression *StringExp::castTo(Scope *sc, Type *t)
{
/* This follows copy-on-write; any changes to 'this'
* will result in a copy.
* The this->string member is considered immutable.
*/
int copied = 0;
//printf("StringExp::castTo(t = %s), '%s' committed = %d\n", t->toChars(), toChars(), committed);
if (!committed && t->ty == Tpointer && t->nextOf()->ty == Tvoid)
{
error("cannot convert string literal to void*");
return new ErrorExp();
}
StringExp *se = this;
if (!committed)