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Issue 6404 - Cannot check ref-ness of auto ref parameter in template constraint #282

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Merged
WalterBright merged 1 commit into from
Jul 30, 2011
Merged

Issue 6404 - Cannot check ref-ness of auto ref parameter in template constraint #282

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41 changes: 26 additions & 15 deletions src/template.c
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Original file line number Diff line number Diff line change
Expand Up @@ -589,7 +589,7 @@ int TemplateDeclaration::overloadInsert(Dsymbol *s)
* Declare all the function parameters as variables
* and add them to the scope
*/
void TemplateDeclaration::makeParamNamesVisibleInConstraint(Scope *paramscope)
void TemplateDeclaration::makeParamNamesVisibleInConstraint(Scope *paramscope, Expressions *fargs)
{
/* We do this ONLY if there is only one function in the template.
*/
Expand Down Expand Up @@ -619,6 +619,17 @@ void TemplateDeclaration::makeParamNamesVisibleInConstraint(Scope *paramscope)
v->storage_class |= STCvariadic;

v->storage_class |= fparam->storageClass & (STCin | STCout | STCref | STClazy | STCfinal | STC_TYPECTOR | STCnodtor);
if (fparam->storageClass & STCauto)
{
if (fargs && i < fargs->dim)
{ Expression *farg = fargs->tdata()[i];
if (farg->isLvalue())
; // ref parameter
else
v->storage_class &= ~STCref; // value parameter
}
}

v->semantic(paramscope);
if (!paramscope->insert(v))
error("parameter %s.%s is already defined", toChars(), v->toChars());
Expand All @@ -641,7 +652,7 @@ void TemplateDeclaration::makeParamNamesVisibleInConstraint(Scope *paramscope)
*/

MATCH TemplateDeclaration::matchWithInstance(TemplateInstance *ti,
Objects *dedtypes, int flag)
Objects *dedtypes, Expressions *fargs, int flag)
{ MATCH m;
int dedtypes_dim = dedtypes->dim;

Expand Down Expand Up @@ -739,7 +750,7 @@ MATCH TemplateDeclaration::matchWithInstance(TemplateInstance *ti,
if (m && constraint && !(flag & 1))
{ /* Check to see if constraint is satisfied.
*/
makeParamNamesVisibleInConstraint(paramscope);
makeParamNamesVisibleInConstraint(paramscope, fargs);
Expression *e = constraint->syntaxCopy();
Scope *sc = paramscope->push();
sc->flags |= SCOPEstaticif;
Expand Down Expand Up @@ -808,7 +819,7 @@ MATCH TemplateDeclaration::matchWithInstance(TemplateInstance *ti,
* 0 td2 is more specialized than this
*/

MATCH TemplateDeclaration::leastAsSpecialized(TemplateDeclaration *td2)
MATCH TemplateDeclaration::leastAsSpecialized(TemplateDeclaration *td2, Expressions *fargs)
{
/* This works by taking the template parameters to this template
* declaration and feeding them to td2 as if it were a template
Expand Down Expand Up @@ -846,7 +857,7 @@ MATCH TemplateDeclaration::leastAsSpecialized(TemplateDeclaration *td2)
dedtypes.setDim(td2->parameters->dim);

// Attempt a type deduction
MATCH m = td2->matchWithInstance(&ti, &dedtypes, 1);
MATCH m = td2->matchWithInstance(&ti, &dedtypes, fargs, 1);
if (m)
{
/* A non-variadic template is more specialized than a
Expand Down Expand Up @@ -1334,7 +1345,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
if (constraint)
{ /* Check to see if constraint is satisfied.
*/
makeParamNamesVisibleInConstraint(paramscope);
makeParamNamesVisibleInConstraint(paramscope, fargs);
Expression *e = constraint->syntaxCopy();
paramscope->flags |= SCOPEstaticif;

Expand Down Expand Up @@ -1573,8 +1584,8 @@ FuncDeclaration *TemplateDeclaration::deduceFunctionTemplate(Scope *sc, Loc loc,

{
// Disambiguate by picking the most specialized TemplateDeclaration
MATCH c1 = td->leastAsSpecialized(td_best);
MATCH c2 = td_best->leastAsSpecialized(td);
MATCH c1 = td->leastAsSpecialized(td_best, fargs);
MATCH c2 = td_best->leastAsSpecialized(td, fargs);
//printf("c1 = %d, c2 = %d\n", c1, c2);

if (c1 > c2)
Expand Down Expand Up @@ -3797,7 +3808,7 @@ void TemplateInstance::semantic(Scope *sc, Expressions *fargs)
assert((size_t)tempdecl->scope > 0x10000);
// Deduce tdtypes
tdtypes.setDim(tempdecl->parameters->dim);
if (!tempdecl->matchWithInstance(this, &tdtypes, 2))
if (!tempdecl->matchWithInstance(this, &tdtypes, fargs, 2))
{
error("incompatible arguments for template instantiation");
inst = this;
Expand All @@ -3818,7 +3829,7 @@ void TemplateInstance::semantic(Scope *sc, Expressions *fargs)

tempdecl = findTemplateDeclaration(sc);
if (tempdecl)
tempdecl = findBestMatch(sc);
tempdecl = findBestMatch(sc, fargs);
if (!tempdecl || global.errors)
{ inst = this;
//printf("error return %p, %d\n", tempdecl, global.errors);
Expand Down Expand Up @@ -4446,7 +4457,7 @@ TemplateDeclaration *TemplateInstance::findTemplateDeclaration(Scope *sc)
return tempdecl;
}

TemplateDeclaration *TemplateInstance::findBestMatch(Scope *sc)
TemplateDeclaration *TemplateInstance::findBestMatch(Scope *sc, Expressions *fargs)
{
/* Since there can be multiple TemplateDeclaration's with the same
* name, look for the best match.
Expand Down Expand Up @@ -4493,7 +4504,7 @@ TemplateDeclaration *TemplateInstance::findBestMatch(Scope *sc)
dedtypes.setDim(td->parameters->dim);
dedtypes.zero();
assert(td->semanticRun);
m = td->matchWithInstance(this, &dedtypes, 0);
m = td->matchWithInstance(this, &dedtypes, fargs, 0);
//printf("matchWithInstance = %d\n", m);
if (!m) // no match at all
continue;
Expand All @@ -4505,8 +4516,8 @@ TemplateDeclaration *TemplateInstance::findBestMatch(Scope *sc)

{
// Disambiguate by picking the most specialized TemplateDeclaration
MATCH c1 = td->leastAsSpecialized(td_best);
MATCH c2 = td_best->leastAsSpecialized(td);
MATCH c1 = td->leastAsSpecialized(td_best, fargs);
MATCH c2 = td_best->leastAsSpecialized(td, fargs);
//printf("c1 = %d, c2 = %d\n", c1, c2);

if (c1 > c2)
Expand Down Expand Up @@ -5263,7 +5274,7 @@ void TemplateMixin::semantic(Scope *sc)
if (errors)
return;

tempdecl = findBestMatch(sc);
tempdecl = findBestMatch(sc, NULL);
if (!tempdecl)
{ inst = this;
return; // error recovery
Expand Down
8 changes: 4 additions & 4 deletions src/template.h
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Original file line number Diff line number Diff line change
Expand Up @@ -84,8 +84,8 @@ struct TemplateDeclaration : ScopeDsymbol
void toJsonBuffer(OutBuffer *buf);
// void toDocBuffer(OutBuffer *buf);

MATCH matchWithInstance(TemplateInstance *ti, Objects *atypes, int flag);
MATCH leastAsSpecialized(TemplateDeclaration *td2);
MATCH matchWithInstance(TemplateInstance *ti, Objects *atypes, Expressions *fargs, int flag);
MATCH leastAsSpecialized(TemplateDeclaration *td2, Expressions *fargs);

MATCH deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objects *targsi, Expression *ethis, Expressions *fargs, Objects *dedargs);
FuncDeclaration *deduceFunctionTemplate(Scope *sc, Loc loc, Objects *targsi, Expression *ethis, Expressions *fargs, int flags = 0);
Expand All @@ -96,7 +96,7 @@ struct TemplateDeclaration : ScopeDsymbol
TemplateTupleParameter *isVariadic();
int isOverloadable();

void makeParamNamesVisibleInConstraint(Scope *paramscope);
void makeParamNamesVisibleInConstraint(Scope *paramscope, Expressions *fargs);
};

struct TemplateParameter
Expand Down Expand Up @@ -324,7 +324,7 @@ struct TemplateInstance : ScopeDsymbol
static void semanticTiargs(Loc loc, Scope *sc, Objects *tiargs, int flags);
void semanticTiargs(Scope *sc);
TemplateDeclaration *findTemplateDeclaration(Scope *sc);
TemplateDeclaration *findBestMatch(Scope *sc);
TemplateDeclaration *findBestMatch(Scope *sc, Expressions *fargs);
void declareParameters(Scope *sc);
int hasNestedArgs(Objects *tiargs);
Identifier *genIdent(Objects *args);
Expand Down
21 changes: 21 additions & 0 deletions test/runnable/template9.d
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Original file line number Diff line number Diff line change
Expand Up @@ -201,6 +201,26 @@ template _ElemType(T) {
alias r type;
}

/**********************************/
// 6404

// receive only rvalue
void rvalue(T)(auto ref T x) if (!__traits(isRef, x)) {}

// receive only lvalue
void lvalue(T)(auto ref T x) if ( __traits(isRef, x)) {}

void test6404()
{
int n;

static assert(!__traits(compiles, rvalue(n)));
static assert( __traits(compiles, rvalue(0)));

static assert( __traits(compiles, lvalue(n)));
static assert(!__traits(compiles, lvalue(0)));
}

/**********************************/

int main()
Expand All @@ -214,6 +234,7 @@ int main()
test7();
test8();
test9();
test6404();

printf("Success\n");
return 0;
Expand Down