P0184R0: Allow types of 'begin' and 'end' expressions in range-based for loops to differ.

llvm-svn: 263895
This commit is contained in:
Richard Smith 2016-03-20 10:33:40 +00:00
parent 25a63b1bcc
commit 01694c340d
15 changed files with 109 additions and 68 deletions

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@ -127,7 +127,7 @@ public:
/// can be extracted using getLoopVariable and getRangeInit.
class CXXForRangeStmt : public Stmt {
SourceLocation ForLoc;
enum { RANGE, BEGINEND, COND, INC, LOOPVAR, BODY, END };
enum { RANGE, BEGINSTMT, ENDSTMT, COND, INC, LOOPVAR, BODY, END };
// SubExprs[RANGE] is an expression or declstmt.
// SubExprs[COND] and SubExprs[INC] are expressions.
Stmt *SubExprs[END];
@ -137,7 +137,7 @@ class CXXForRangeStmt : public Stmt {
friend class ASTStmtReader;
public:
CXXForRangeStmt(DeclStmt *Range, DeclStmt *BeginEnd,
CXXForRangeStmt(DeclStmt *Range, DeclStmt *Begin, DeclStmt *End,
Expr *Cond, Expr *Inc, DeclStmt *LoopVar, Stmt *Body,
SourceLocation FL, SourceLocation CAL, SourceLocation CL,
SourceLocation RPL);
@ -152,9 +152,10 @@ public:
DeclStmt *getRangeStmt() { return cast<DeclStmt>(SubExprs[RANGE]); }
DeclStmt *getBeginEndStmt() {
return cast_or_null<DeclStmt>(SubExprs[BEGINEND]);
DeclStmt *getBeginStmt() {
return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);
}
DeclStmt *getEndStmt() { return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]); }
Expr *getCond() { return cast_or_null<Expr>(SubExprs[COND]); }
Expr *getInc() { return cast_or_null<Expr>(SubExprs[INC]); }
DeclStmt *getLoopVarStmt() { return cast<DeclStmt>(SubExprs[LOOPVAR]); }
@ -163,8 +164,11 @@ public:
const DeclStmt *getRangeStmt() const {
return cast<DeclStmt>(SubExprs[RANGE]);
}
const DeclStmt *getBeginEndStmt() const {
return cast_or_null<DeclStmt>(SubExprs[BEGINEND]);
const DeclStmt *getBeginStmt() const {
return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);
}
const DeclStmt *getEndStmt() const {
return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]);
}
const Expr *getCond() const {
return cast_or_null<Expr>(SubExprs[COND]);
@ -179,7 +183,8 @@ public:
void setRangeInit(Expr *E) { SubExprs[RANGE] = reinterpret_cast<Stmt*>(E); }
void setRangeStmt(Stmt *S) { SubExprs[RANGE] = S; }
void setBeginEndStmt(Stmt *S) { SubExprs[BEGINEND] = S; }
void setBeginStmt(Stmt *S) { SubExprs[BEGINSTMT] = S; }
void setEndStmt(Stmt *S) { SubExprs[ENDSTMT] = S; }
void setCond(Expr *E) { SubExprs[COND] = reinterpret_cast<Stmt*>(E); }
void setInc(Expr *E) { SubExprs[INC] = reinterpret_cast<Stmt*>(E); }
void setLoopVarStmt(Stmt *S) { SubExprs[LOOPVAR] = S; }

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@ -30,23 +30,6 @@ def warn_redundant_loop_iteration : Warning<
InGroup<ForLoopAnalysis>, DefaultIgnore;
def note_loop_iteration_here : Note<"%select{decremented|incremented}0 here">;
def warn_for_range_const_reference_copy : Warning<
"loop variable %0 "
"%diff{has type $ but is initialized with type $"
"| is initialized with a value of a different type}1,2 resulting in a copy">,
InGroup<RangeLoopAnalysis>, DefaultIgnore;
def note_use_type_or_non_reference : Note<
"use non-reference type %0 to keep the copy or type %1 to prevent copying">;
def warn_for_range_variable_always_copy : Warning<
"loop variable %0 is always a copy because the range of type %1 does not "
"return a reference">,
InGroup<RangeLoopAnalysis>, DefaultIgnore;
def note_use_non_reference_type : Note<"use non-reference type %0">;
def warn_for_range_copy : Warning<
"loop variable %0 of type %1 creates a copy from type %2">,
InGroup<RangeLoopAnalysis>, DefaultIgnore;
def note_use_reference_type : Note<"use reference type %0 to prevent copying">;
def warn_duplicate_enum_values : Warning<
"element %0 has been implicitly assigned %1 which another element has "
"been assigned">, InGroup<DiagGroup<"duplicate-enum">>, DefaultIgnore;
@ -1920,8 +1903,12 @@ def err_for_range_iter_deduction_failure : Error<
"cannot use type %0 as an iterator">;
def err_for_range_member_begin_end_mismatch : Error<
"range type %0 has '%select{begin|end}1' member but no '%select{end|begin}1' member">;
def err_for_range_begin_end_types_differ : Error<
"'begin' and 'end' must return the same type (got %0 and %1)">;
def ext_for_range_begin_end_types_differ : ExtWarn<
"'begin' and 'end' returning different types (%0 and %1) is a C++1z extension">,
InGroup<CXX1z>;
def warn_for_range_begin_end_types_differ : Warning<
"'begin' and 'end' returning different types (%0 and %1) is incompatible "
"with C++ standards before C++1z">, InGroup<CXXPre1zCompat>, DefaultIgnore;
def note_in_for_range: Note<
"when looking up '%select{begin|end}0' function for range expression "
"of type %1">;
@ -1938,6 +1925,22 @@ def note_for_range_invalid_iterator : Note <
"in implicit call to 'operator%select{!=|*|++}0' for iterator of type %1">;
def note_for_range_begin_end : Note<
"selected '%select{begin|end}0' %select{function|template }1%2 with iterator type %3">;
def warn_for_range_const_reference_copy : Warning<
"loop variable %0 "
"%diff{has type $ but is initialized with type $"
"| is initialized with a value of a different type}1,2 resulting in a copy">,
InGroup<RangeLoopAnalysis>, DefaultIgnore;
def note_use_type_or_non_reference : Note<
"use non-reference type %0 to keep the copy or type %1 to prevent copying">;
def warn_for_range_variable_always_copy : Warning<
"loop variable %0 is always a copy because the range of type %1 does not "
"return a reference">,
InGroup<RangeLoopAnalysis>, DefaultIgnore;
def note_use_non_reference_type : Note<"use non-reference type %0">;
def warn_for_range_copy : Warning<
"loop variable %0 of type %1 creates a copy from type %2">,
InGroup<RangeLoopAnalysis>, DefaultIgnore;
def note_use_reference_type : Note<"use reference type %0 to prevent copying">;
// C++11 constexpr
def warn_cxx98_compat_constexpr : Warning<

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@ -3376,7 +3376,7 @@ public:
StmtResult BuildCXXForRangeStmt(SourceLocation ForLoc,
SourceLocation CoawaitLoc,
SourceLocation ColonLoc,
Stmt *RangeDecl, Stmt *BeginEndDecl,
Stmt *RangeDecl, Stmt *Begin, Stmt *End,
Expr *Cond, Expr *Inc,
Stmt *LoopVarDecl,
SourceLocation RParenLoc,

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@ -4940,9 +4940,13 @@ Stmt *ASTNodeImporter::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
dyn_cast_or_null<DeclStmt>(Importer.Import(S->getRangeStmt()));
if (!ToRange && S->getRangeStmt())
return nullptr;
DeclStmt *ToBeginEnd =
dyn_cast_or_null<DeclStmt>(Importer.Import(S->getBeginEndStmt()));
if (!ToBeginEnd && S->getBeginEndStmt())
DeclStmt *ToBegin =
dyn_cast_or_null<DeclStmt>(Importer.Import(S->getBeginStmt()));
if (!ToBegin && S->getBeginStmt())
return nullptr;
DeclStmt *ToEnd =
dyn_cast_or_null<DeclStmt>(Importer.Import(S->getEndStmt()));
if (!ToEnd && S->getEndStmt())
return nullptr;
Expr *ToCond = Importer.Import(S->getCond());
if (!ToCond && S->getCond())
@ -4961,7 +4965,7 @@ Stmt *ASTNodeImporter::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
SourceLocation ToCoawaitLoc = Importer.Import(S->getCoawaitLoc());
SourceLocation ToColonLoc = Importer.Import(S->getColonLoc());
SourceLocation ToRParenLoc = Importer.Import(S->getRParenLoc());
return new (Importer.getToContext()) CXXForRangeStmt(ToRange, ToBeginEnd,
return new (Importer.getToContext()) CXXForRangeStmt(ToRange, ToBegin, ToEnd,
ToCond, ToInc,
ToLoopVar, ToBody,
ToForLoc, ToCoawaitLoc,

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@ -3647,7 +3647,10 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info,
return ESR;
// Create the __begin and __end iterators.
ESR = EvaluateStmt(Result, Info, FS->getBeginEndStmt());
ESR = EvaluateStmt(Result, Info, FS->getBeginStmt());
if (ESR != ESR_Succeeded)
return ESR;
ESR = EvaluateStmt(Result, Info, FS->getEndStmt());
if (ESR != ESR_Succeeded)
return ESR;

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@ -49,7 +49,8 @@ CXXTryStmt::CXXTryStmt(SourceLocation tryLoc, Stmt *tryBlock,
std::copy(handlers.begin(), handlers.end(), Stmts + 1);
}
CXXForRangeStmt::CXXForRangeStmt(DeclStmt *Range, DeclStmt *BeginEndStmt,
CXXForRangeStmt::CXXForRangeStmt(DeclStmt *Range,
DeclStmt *BeginStmt, DeclStmt *EndStmt,
Expr *Cond, Expr *Inc, DeclStmt *LoopVar,
Stmt *Body, SourceLocation FL,
SourceLocation CAL, SourceLocation CL,
@ -57,7 +58,8 @@ CXXForRangeStmt::CXXForRangeStmt(DeclStmt *Range, DeclStmt *BeginEndStmt,
: Stmt(CXXForRangeStmtClass), ForLoc(FL), CoawaitLoc(CAL), ColonLoc(CL),
RParenLoc(RPL) {
SubExprs[RANGE] = Range;
SubExprs[BEGINEND] = BeginEndStmt;
SubExprs[BEGINSTMT] = BeginStmt;
SubExprs[ENDSTMT] = EndStmt;
SubExprs[COND] = Cond;
SubExprs[INC] = Inc;
SubExprs[LOOPVAR] = LoopVar;

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@ -3397,8 +3397,10 @@ CFGBlock *CFGBuilder::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
// Create local scopes and destructors for range, begin and end variables.
if (Stmt *Range = S->getRangeStmt())
addLocalScopeForStmt(Range);
if (Stmt *BeginEnd = S->getBeginEndStmt())
addLocalScopeForStmt(BeginEnd);
if (Stmt *Begin = S->getBeginStmt())
addLocalScopeForStmt(Begin);
if (Stmt *End = S->getEndStmt())
addLocalScopeForStmt(End);
addAutomaticObjDtors(ScopePos, save_scope_pos.get(), S);
LocalScope::const_iterator ContinueScopePos = ScopePos;
@ -3489,7 +3491,8 @@ CFGBlock *CFGBuilder::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
// Add the initialization statements.
Block = createBlock();
addStmt(S->getBeginEndStmt());
addStmt(S->getBeginStmt());
addStmt(S->getEndStmt());
return addStmt(S->getRangeStmt());
}

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@ -870,7 +870,8 @@ CodeGenFunction::EmitCXXForRangeStmt(const CXXForRangeStmt &S,
// Evaluate the first pieces before the loop.
EmitStmt(S.getRangeStmt());
EmitStmt(S.getBeginEndStmt());
EmitStmt(S.getBeginStmt());
EmitStmt(S.getEndStmt());
// Start the loop with a block that tests the condition.
// If there's an increment, the continue scope will be overwritten

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@ -409,7 +409,8 @@ struct ComputeRegionCounts : public ConstStmtVisitor<ComputeRegionCounts> {
RecordStmtCount(S);
Visit(S->getLoopVarStmt());
Visit(S->getRangeStmt());
Visit(S->getBeginEndStmt());
Visit(S->getBeginStmt());
Visit(S->getEndStmt());
uint64_t ParentCount = CurrentCount;
BreakContinueStack.push_back(BreakContinue());

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@ -2033,8 +2033,9 @@ StmtResult Sema::ActOnCXXForRangeStmt(Scope *S, SourceLocation ForLoc,
}
return BuildCXXForRangeStmt(ForLoc, CoawaitLoc, ColonLoc, RangeDecl.get(),
/*BeginEndDecl=*/nullptr, /*Cond=*/nullptr,
/*Inc=*/nullptr, DS, RParenLoc, Kind);
/*BeginStmt=*/nullptr, /*EndStmt=*/nullptr,
/*Cond=*/nullptr, /*Inc=*/nullptr,
DS, RParenLoc, Kind);
}
/// \brief Create the initialization, compare, and increment steps for
@ -2184,8 +2185,8 @@ struct InvalidateOnErrorScope {
/// BuildCXXForRangeStmt - Build or instantiate a C++11 for-range statement.
StmtResult
Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation CoawaitLoc,
SourceLocation ColonLoc,
Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond,
SourceLocation ColonLoc, Stmt *RangeDecl,
Stmt *Begin, Stmt *End, Expr *Cond,
Expr *Inc, Stmt *LoopVarDecl,
SourceLocation RParenLoc, BuildForRangeKind Kind) {
// FIXME: This should not be used during template instantiation. We should
@ -2211,7 +2212,8 @@ Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation CoawaitLoc,
InvalidateOnErrorScope Invalidate(*this, LoopVar,
LoopVar->getType()->isUndeducedType());
StmtResult BeginEndDecl = BeginEnd;
StmtResult BeginDeclStmt = Begin;
StmtResult EndDeclStmt = End;
ExprResult NotEqExpr = Cond, IncrExpr = Inc;
if (RangeVarType->isDependentType()) {
@ -2222,7 +2224,7 @@ Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation CoawaitLoc,
// them in properly when we instantiate the loop.
if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check)
LoopVar->setType(SubstAutoType(LoopVar->getType(), Context.DependentTy));
} else if (!BeginEndDecl.get()) {
} else if (!BeginDeclStmt.get()) {
SourceLocation RangeLoc = RangeVar->getLocation();
const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType();
@ -2347,20 +2349,21 @@ Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation CoawaitLoc,
"invalid range expression in for loop");
// C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same.
// C++1z removes this restriction.
QualType BeginType = BeginVar->getType(), EndType = EndVar->getType();
if (!Context.hasSameType(BeginType, EndType)) {
Diag(RangeLoc, diag::err_for_range_begin_end_types_differ)
<< BeginType << EndType;
Diag(RangeLoc, getLangOpts().CPlusPlus1z
? diag::warn_for_range_begin_end_types_differ
: diag::ext_for_range_begin_end_types_differ)
<< BeginType << EndType;
NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin);
NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end);
}
Decl *BeginEndDecls[] = { BeginVar, EndVar };
// Claim the type doesn't contain auto: we've already done the checking.
DeclGroupPtrTy BeginEndGroup =
BuildDeclaratorGroup(MutableArrayRef<Decl *>(BeginEndDecls, 2),
/*TypeMayContainAuto=*/ false);
BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc);
BeginDeclStmt =
ActOnDeclStmt(ConvertDeclToDeclGroup(BeginVar), ColonLoc, ColonLoc);
EndDeclStmt =
ActOnDeclStmt(ConvertDeclToDeclGroup(EndVar), ColonLoc, ColonLoc);
const QualType BeginRefNonRefType = BeginType.getNonReferenceType();
ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType,
@ -2435,7 +2438,8 @@ Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation CoawaitLoc,
return StmtResult();
return new (Context) CXXForRangeStmt(
RangeDS, cast_or_null<DeclStmt>(BeginEndDecl.get()), NotEqExpr.get(),
RangeDS, cast_or_null<DeclStmt>(BeginDeclStmt.get()),
cast_or_null<DeclStmt>(EndDeclStmt.get()), NotEqExpr.get(),
IncrExpr.get(), LoopVarDS, /*Body=*/nullptr, ForLoc, CoawaitLoc,
ColonLoc, RParenLoc);
}

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@ -1840,7 +1840,7 @@ public:
StmtResult RebuildCXXForRangeStmt(SourceLocation ForLoc,
SourceLocation CoawaitLoc,
SourceLocation ColonLoc,
Stmt *Range, Stmt *BeginEnd,
Stmt *Range, Stmt *Begin, Stmt *End,
Expr *Cond, Expr *Inc,
Stmt *LoopVar,
SourceLocation RParenLoc) {
@ -1862,7 +1862,7 @@ public:
}
return getSema().BuildCXXForRangeStmt(ForLoc, CoawaitLoc, ColonLoc,
Range, BeginEnd,
Range, Begin, End,
Cond, Inc, LoopVar, RParenLoc,
Sema::BFRK_Rebuild);
}
@ -6889,8 +6889,11 @@ TreeTransform<Derived>::TransformCXXForRangeStmt(CXXForRangeStmt *S) {
if (Range.isInvalid())
return StmtError();
StmtResult BeginEnd = getDerived().TransformStmt(S->getBeginEndStmt());
if (BeginEnd.isInvalid())
StmtResult Begin = getDerived().TransformStmt(S->getBeginStmt());
if (Begin.isInvalid())
return StmtError();
StmtResult End = getDerived().TransformStmt(S->getEndStmt());
if (End.isInvalid())
return StmtError();
ExprResult Cond = getDerived().TransformExpr(S->getCond());
@ -6916,14 +6919,16 @@ TreeTransform<Derived>::TransformCXXForRangeStmt(CXXForRangeStmt *S) {
StmtResult NewStmt = S;
if (getDerived().AlwaysRebuild() ||
Range.get() != S->getRangeStmt() ||
BeginEnd.get() != S->getBeginEndStmt() ||
Begin.get() != S->getBeginStmt() ||
End.get() != S->getEndStmt() ||
Cond.get() != S->getCond() ||
Inc.get() != S->getInc() ||
LoopVar.get() != S->getLoopVarStmt()) {
NewStmt = getDerived().RebuildCXXForRangeStmt(S->getForLoc(),
S->getCoawaitLoc(),
S->getColonLoc(), Range.get(),
BeginEnd.get(), Cond.get(),
Begin.get(), End.get(),
Cond.get(),
Inc.get(), LoopVar.get(),
S->getRParenLoc());
if (NewStmt.isInvalid())
@ -6940,7 +6945,8 @@ TreeTransform<Derived>::TransformCXXForRangeStmt(CXXForRangeStmt *S) {
NewStmt = getDerived().RebuildCXXForRangeStmt(S->getForLoc(),
S->getCoawaitLoc(),
S->getColonLoc(), Range.get(),
BeginEnd.get(), Cond.get(),
Begin.get(), End.get(),
Cond.get(),
Inc.get(), LoopVar.get(),
S->getRParenLoc());
if (NewStmt.isInvalid())

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@ -1207,7 +1207,8 @@ void ASTStmtReader::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
S->ColonLoc = ReadSourceLocation(Record, Idx);
S->RParenLoc = ReadSourceLocation(Record, Idx);
S->setRangeStmt(Reader.ReadSubStmt());
S->setBeginEndStmt(Reader.ReadSubStmt());
S->setBeginStmt(Reader.ReadSubStmt());
S->setEndStmt(Reader.ReadSubStmt());
S->setCond(Reader.ReadSubExpr());
S->setInc(Reader.ReadSubExpr());
S->setLoopVarStmt(Reader.ReadSubStmt());

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@ -1161,7 +1161,8 @@ void ASTStmtWriter::VisitCXXForRangeStmt(CXXForRangeStmt *S) {
Writer.AddSourceLocation(S->getColonLoc(), Record);
Writer.AddSourceLocation(S->getRParenLoc(), Record);
Writer.AddStmt(S->getRangeStmt());
Writer.AddStmt(S->getBeginEndStmt());
Writer.AddStmt(S->getBeginStmt());
Writer.AddStmt(S->getEndStmt());
Writer.AddStmt(S->getCond());
Writer.AddStmt(S->getInc());
Writer.AddStmt(S->getLoopVarStmt());

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@ -1,4 +1,6 @@
// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify %s
// RUN: %clang_cc1 -std=c++1z -fsyntax-only -verify %s
struct pr12960 {
int begin;
@ -118,10 +120,15 @@ void g() {
;
struct Differ {
int *begin(); // expected-note {{selected 'begin' function with iterator type 'int *'}}
null_t end(); // expected-note {{selected 'end' function with iterator type 'null_t'}}
int *begin();
null_t end();
};
for (auto a : Differ()) // expected-error {{'begin' and 'end' must return the same type (got 'int *' and 'null_t')}}
for (auto a : Differ())
#if __cplusplus <= 201402L
// expected-warning@-2 {{'begin' and 'end' returning different types ('int *' and 'null_t') is a C++1z extension}}
// expected-note@-6 {{selected 'begin' function with iterator type 'int *'}}
// expected-note@-6 {{selected 'end' function with iterator type 'null_t'}}
#endif
;
for (void f() : "error") // expected-error {{for range declaration must declare a variable}}
@ -129,7 +136,7 @@ void g() {
for (extern int a : A()) {} // expected-error {{loop variable 'a' may not be declared 'extern'}}
for (static int a : A()) {} // expected-error {{loop variable 'a' may not be declared 'static'}}
for (register int a : A()) {} // expected-error {{loop variable 'a' may not be declared 'register'}} expected-warning {{deprecated}}
for (register int a : A()) {} // expected-error {{loop variable 'a' may not be declared 'register'}} expected-warning 0-1{{register}} expected-error 0-1{{register}}
for (constexpr int a : X::C()) {} // OK per CWG issue #1204.
for (auto u : X::NoBeginADL()) { // expected-error {{invalid range expression of type 'X::NoBeginADL'; no viable 'begin' function available}}

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@ -654,7 +654,7 @@ as the draft C++1z standard evolves.</p>
<tr>
<td>Differing <tt>begin</tt> and <tt>end</tt> types in range-based <tt>for</tt></td>
<td><a href="http://wg21.link/p0184r0">P0184R0</a></td>
<td class="none" align="center">No</td>
<td class="svn" align="center">SVN</td>
</tr>
<tr>
<td>Lambda capture of <tt>*this</tt></td>