1 //===--- Overload.h - C++ Overloading ---------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the data structures and types used in C++
11 // overload resolution.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_SEMA_OVERLOAD_H
16 #define LLVM_CLANG_SEMA_OVERLOAD_H
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/DeclTemplate.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/TemplateBase.h"
22 #include "clang/AST/Type.h"
23 #include "clang/AST/UnresolvedSet.h"
24 #include "clang/Sema/SemaFixItUtils.h"
25 #include "clang/Sema/TemplateDeduction.h"
26 #include "llvm/ADT/SmallPtrSet.h"
27 #include "llvm/ADT/SmallVector.h"
28 #include "llvm/Support/Allocator.h"
32 class CXXConstructorDecl;
33 class CXXConversionDecl;
37 /// OverloadingResult - Capture the result of performing overload
39 enum OverloadingResult {
40 OR_Success, ///< Overload resolution succeeded.
41 OR_No_Viable_Function, ///< No viable function found.
42 OR_Ambiguous, ///< Ambiguous candidates found.
43 OR_Deleted ///< Succeeded, but refers to a deleted function.
46 enum OverloadCandidateDisplayKind {
47 /// Requests that all candidates be shown. Viable candidates will
51 /// Requests that only viable candidates be shown.
55 /// ImplicitConversionKind - The kind of implicit conversion used to
56 /// convert an argument to a parameter's type. The enumerator values
57 /// match with Table 9 of (C++ 13.3.3.1.1) and are listed such that
58 /// better conversion kinds have smaller values.
59 enum ImplicitConversionKind {
60 ICK_Identity = 0, ///< Identity conversion (no conversion)
61 ICK_Lvalue_To_Rvalue, ///< Lvalue-to-rvalue conversion (C++ 4.1)
62 ICK_Array_To_Pointer, ///< Array-to-pointer conversion (C++ 4.2)
63 ICK_Function_To_Pointer, ///< Function-to-pointer (C++ 4.3)
64 ICK_NoReturn_Adjustment, ///< Removal of noreturn from a type (Clang)
65 ICK_Qualification, ///< Qualification conversions (C++ 4.4)
66 ICK_Integral_Promotion, ///< Integral promotions (C++ 4.5)
67 ICK_Floating_Promotion, ///< Floating point promotions (C++ 4.6)
68 ICK_Complex_Promotion, ///< Complex promotions (Clang extension)
69 ICK_Integral_Conversion, ///< Integral conversions (C++ 4.7)
70 ICK_Floating_Conversion, ///< Floating point conversions (C++ 4.8)
71 ICK_Complex_Conversion, ///< Complex conversions (C99 6.3.1.6)
72 ICK_Floating_Integral, ///< Floating-integral conversions (C++ 4.9)
73 ICK_Pointer_Conversion, ///< Pointer conversions (C++ 4.10)
74 ICK_Pointer_Member, ///< Pointer-to-member conversions (C++ 4.11)
75 ICK_Boolean_Conversion, ///< Boolean conversions (C++ 4.12)
76 ICK_Compatible_Conversion, ///< Conversions between compatible types in C99
77 ICK_Derived_To_Base, ///< Derived-to-base (C++ [over.best.ics])
78 ICK_Vector_Conversion, ///< Vector conversions
79 ICK_Vector_Splat, ///< A vector splat from an arithmetic type
80 ICK_Complex_Real, ///< Complex-real conversions (C99 6.3.1.7)
81 ICK_Block_Pointer_Conversion, ///< Block Pointer conversions
82 ICK_TransparentUnionConversion, ///< Transparent Union Conversions
83 ICK_Writeback_Conversion, ///< Objective-C ARC writeback conversion
84 ICK_Zero_Event_Conversion, ///< Zero constant to event (OpenCL1.2 6.12.10)
85 ICK_Num_Conversion_Kinds ///< The number of conversion kinds
88 /// ImplicitConversionCategory - The category of an implicit
89 /// conversion kind. The enumerator values match with Table 9 of
90 /// (C++ 13.3.3.1.1) and are listed such that better conversion
91 /// categories have smaller values.
92 enum ImplicitConversionCategory {
93 ICC_Identity = 0, ///< Identity
94 ICC_Lvalue_Transformation, ///< Lvalue transformation
95 ICC_Qualification_Adjustment, ///< Qualification adjustment
96 ICC_Promotion, ///< Promotion
97 ICC_Conversion ///< Conversion
100 ImplicitConversionCategory
101 GetConversionCategory(ImplicitConversionKind Kind);
103 /// ImplicitConversionRank - The rank of an implicit conversion
104 /// kind. The enumerator values match with Table 9 of (C++
105 /// 13.3.3.1.1) and are listed such that better conversion ranks
106 /// have smaller values.
107 enum ImplicitConversionRank {
108 ICR_Exact_Match = 0, ///< Exact Match
109 ICR_Promotion, ///< Promotion
110 ICR_Conversion, ///< Conversion
111 ICR_Complex_Real_Conversion, ///< Complex <-> Real conversion
112 ICR_Writeback_Conversion ///< ObjC ARC writeback conversion
115 ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind);
117 /// NarrowingKind - The kind of narrowing conversion being performed by a
118 /// standard conversion sequence according to C++11 [dcl.init.list]p7.
120 /// Not a narrowing conversion.
123 /// A narrowing conversion by virtue of the source and destination types.
126 /// A narrowing conversion, because a constant expression got narrowed.
127 NK_Constant_Narrowing,
129 /// A narrowing conversion, because a non-constant-expression variable might
130 /// have got narrowed.
131 NK_Variable_Narrowing
134 /// StandardConversionSequence - represents a standard conversion
135 /// sequence (C++ 13.3.3.1.1). A standard conversion sequence
136 /// contains between zero and three conversions. If a particular
137 /// conversion is not needed, it will be set to the identity conversion
138 /// (ICK_Identity). Note that the three conversions are
139 /// specified as separate members (rather than in an array) so that
140 /// we can keep the size of a standard conversion sequence to a
142 class StandardConversionSequence {
144 /// First -- The first conversion can be an lvalue-to-rvalue
145 /// conversion, array-to-pointer conversion, or
146 /// function-to-pointer conversion.
147 ImplicitConversionKind First : 8;
149 /// Second - The second conversion can be an integral promotion,
150 /// floating point promotion, integral conversion, floating point
151 /// conversion, floating-integral conversion, pointer conversion,
152 /// pointer-to-member conversion, or boolean conversion.
153 ImplicitConversionKind Second : 8;
155 /// Third - The third conversion can be a qualification conversion.
156 ImplicitConversionKind Third : 8;
158 /// \brief Whether this is the deprecated conversion of a
159 /// string literal to a pointer to non-const character data
161 unsigned DeprecatedStringLiteralToCharPtr : 1;
163 /// \brief Whether the qualification conversion involves a change in the
164 /// Objective-C lifetime (for automatic reference counting).
165 unsigned QualificationIncludesObjCLifetime : 1;
167 /// IncompatibleObjC - Whether this is an Objective-C conversion
168 /// that we should warn about (if we actually use it).
169 unsigned IncompatibleObjC : 1;
171 /// ReferenceBinding - True when this is a reference binding
172 /// (C++ [over.ics.ref]).
173 unsigned ReferenceBinding : 1;
175 /// DirectBinding - True when this is a reference binding that is a
176 /// direct binding (C++ [dcl.init.ref]).
177 unsigned DirectBinding : 1;
179 /// \brief Whether this is an lvalue reference binding (otherwise, it's
180 /// an rvalue reference binding).
181 unsigned IsLvalueReference : 1;
183 /// \brief Whether we're binding to a function lvalue.
184 unsigned BindsToFunctionLvalue : 1;
186 /// \brief Whether we're binding to an rvalue.
187 unsigned BindsToRvalue : 1;
189 /// \brief Whether this binds an implicit object argument to a
190 /// non-static member function without a ref-qualifier.
191 unsigned BindsImplicitObjectArgumentWithoutRefQualifier : 1;
193 /// \brief Whether this binds a reference to an object with a different
194 /// Objective-C lifetime qualifier.
195 unsigned ObjCLifetimeConversionBinding : 1;
197 /// FromType - The type that this conversion is converting
198 /// from. This is an opaque pointer that can be translated into a
202 /// ToType - The types that this conversion is converting to in
203 /// each step. This is an opaque pointer that can be translated
207 /// CopyConstructor - The copy constructor that is used to perform
208 /// this conversion, when the conversion is actually just the
209 /// initialization of an object via copy constructor. Such
210 /// conversions are either identity conversions or derived-to-base
212 CXXConstructorDecl *CopyConstructor;
214 void setFromType(QualType T) { FromTypePtr = T.getAsOpaquePtr(); }
215 void setToType(unsigned Idx, QualType T) {
216 assert(Idx < 3 && "To type index is out of range");
217 ToTypePtrs[Idx] = T.getAsOpaquePtr();
219 void setAllToTypes(QualType T) {
220 ToTypePtrs[0] = T.getAsOpaquePtr();
221 ToTypePtrs[1] = ToTypePtrs[0];
222 ToTypePtrs[2] = ToTypePtrs[0];
225 QualType getFromType() const {
226 return QualType::getFromOpaquePtr(FromTypePtr);
228 QualType getToType(unsigned Idx) const {
229 assert(Idx < 3 && "To type index is out of range");
230 return QualType::getFromOpaquePtr(ToTypePtrs[Idx]);
233 void setAsIdentityConversion();
235 bool isIdentityConversion() const {
236 return Second == ICK_Identity && Third == ICK_Identity;
239 ImplicitConversionRank getRank() const;
240 NarrowingKind getNarrowingKind(ASTContext &Context, const Expr *Converted,
241 APValue &ConstantValue,
242 QualType &ConstantType) const;
243 bool isPointerConversionToBool() const;
244 bool isPointerConversionToVoidPointer(ASTContext& Context) const;
248 /// UserDefinedConversionSequence - Represents a user-defined
249 /// conversion sequence (C++ 13.3.3.1.2).
250 struct UserDefinedConversionSequence {
251 /// \brief Represents the standard conversion that occurs before
252 /// the actual user-defined conversion.
254 /// C++11 13.3.3.1.2p1:
255 /// If the user-defined conversion is specified by a constructor
256 /// (12.3.1), the initial standard conversion sequence converts
257 /// the source type to the type required by the argument of the
258 /// constructor. If the user-defined conversion is specified by
259 /// a conversion function (12.3.2), the initial standard
260 /// conversion sequence converts the source type to the implicit
261 /// object parameter of the conversion function.
262 StandardConversionSequence Before;
264 /// EllipsisConversion - When this is true, it means user-defined
265 /// conversion sequence starts with a ... (elipsis) conversion, instead of
266 /// a standard conversion. In this case, 'Before' field must be ignored.
267 // FIXME. I much rather put this as the first field. But there seems to be
268 // a gcc code gen. bug which causes a crash in a test. Putting it here seems
269 // to work around the crash.
270 bool EllipsisConversion : 1;
272 /// HadMultipleCandidates - When this is true, it means that the
273 /// conversion function was resolved from an overloaded set having
274 /// size greater than 1.
275 bool HadMultipleCandidates : 1;
277 /// After - Represents the standard conversion that occurs after
278 /// the actual user-defined conversion.
279 StandardConversionSequence After;
281 /// ConversionFunction - The function that will perform the
282 /// user-defined conversion. Null if the conversion is an
283 /// aggregate initialization from an initializer list.
284 FunctionDecl* ConversionFunction;
286 /// \brief The declaration that we found via name lookup, which might be
287 /// the same as \c ConversionFunction or it might be a using declaration
288 /// that refers to \c ConversionFunction.
289 DeclAccessPair FoundConversionFunction;
294 /// Represents an ambiguous user-defined conversion sequence.
295 struct AmbiguousConversionSequence {
296 typedef SmallVector<FunctionDecl*, 4> ConversionSet;
300 char Buffer[sizeof(ConversionSet)];
302 QualType getFromType() const {
303 return QualType::getFromOpaquePtr(FromTypePtr);
305 QualType getToType() const {
306 return QualType::getFromOpaquePtr(ToTypePtr);
308 void setFromType(QualType T) { FromTypePtr = T.getAsOpaquePtr(); }
309 void setToType(QualType T) { ToTypePtr = T.getAsOpaquePtr(); }
311 ConversionSet &conversions() {
312 return *reinterpret_cast<ConversionSet*>(Buffer);
315 const ConversionSet &conversions() const {
316 return *reinterpret_cast<const ConversionSet*>(Buffer);
319 void addConversion(FunctionDecl *D) {
320 conversions().push_back(D);
323 typedef ConversionSet::iterator iterator;
324 iterator begin() { return conversions().begin(); }
325 iterator end() { return conversions().end(); }
327 typedef ConversionSet::const_iterator const_iterator;
328 const_iterator begin() const { return conversions().begin(); }
329 const_iterator end() const { return conversions().end(); }
333 void copyFrom(const AmbiguousConversionSequence &);
336 /// BadConversionSequence - Records information about an invalid
337 /// conversion sequence.
338 struct BadConversionSequence {
344 lvalue_ref_to_rvalue,
348 // This can be null, e.g. for implicit object arguments.
354 // The type we're converting from (an opaque QualType).
357 // The type we're converting to (an opaque QualType).
361 void init(FailureKind K, Expr *From, QualType To) {
362 init(K, From->getType(), To);
365 void init(FailureKind K, QualType From, QualType To) {
372 QualType getFromType() const { return QualType::getFromOpaquePtr(FromTy); }
373 QualType getToType() const { return QualType::getFromOpaquePtr(ToTy); }
375 void setFromExpr(Expr *E) {
377 setFromType(E->getType());
379 void setFromType(QualType T) { FromTy = T.getAsOpaquePtr(); }
380 void setToType(QualType T) { ToTy = T.getAsOpaquePtr(); }
383 /// ImplicitConversionSequence - Represents an implicit conversion
384 /// sequence, which may be a standard conversion sequence
385 /// (C++ 13.3.3.1.1), user-defined conversion sequence (C++ 13.3.3.1.2),
386 /// or an ellipsis conversion sequence (C++ 13.3.3.1.3).
387 class ImplicitConversionSequence {
389 /// Kind - The kind of implicit conversion sequence. BadConversion
390 /// specifies that there is no conversion from the source type to
391 /// the target type. AmbiguousConversion represents the unique
392 /// ambiguous conversion (C++0x [over.best.ics]p10).
394 StandardConversion = 0,
395 UserDefinedConversion,
403 Uninitialized = BadConversion + 1
406 /// ConversionKind - The kind of implicit conversion sequence.
407 unsigned ConversionKind : 30;
409 /// \brief Whether the target is really a std::initializer_list, and the
410 /// sequence only represents the worst element conversion.
411 bool StdInitializerListElement : 1;
413 void setKind(Kind K) {
419 if (ConversionKind == AmbiguousConversion) Ambiguous.destruct();
424 /// When ConversionKind == StandardConversion, provides the
425 /// details of the standard conversion sequence.
426 StandardConversionSequence Standard;
428 /// When ConversionKind == UserDefinedConversion, provides the
429 /// details of the user-defined conversion sequence.
430 UserDefinedConversionSequence UserDefined;
432 /// When ConversionKind == AmbiguousConversion, provides the
433 /// details of the ambiguous conversion.
434 AmbiguousConversionSequence Ambiguous;
436 /// When ConversionKind == BadConversion, provides the details
437 /// of the bad conversion.
438 BadConversionSequence Bad;
441 ImplicitConversionSequence()
442 : ConversionKind(Uninitialized), StdInitializerListElement(false)
444 ~ImplicitConversionSequence() {
447 ImplicitConversionSequence(const ImplicitConversionSequence &Other)
448 : ConversionKind(Other.ConversionKind),
449 StdInitializerListElement(Other.StdInitializerListElement)
451 switch (ConversionKind) {
452 case Uninitialized: break;
453 case StandardConversion: Standard = Other.Standard; break;
454 case UserDefinedConversion: UserDefined = Other.UserDefined; break;
455 case AmbiguousConversion: Ambiguous.copyFrom(Other.Ambiguous); break;
456 case EllipsisConversion: break;
457 case BadConversion: Bad = Other.Bad; break;
461 ImplicitConversionSequence &
462 operator=(const ImplicitConversionSequence &Other) {
464 new (this) ImplicitConversionSequence(Other);
468 Kind getKind() const {
469 assert(isInitialized() && "querying uninitialized conversion");
470 return Kind(ConversionKind);
473 /// \brief Return a ranking of the implicit conversion sequence
474 /// kind, where smaller ranks represent better conversion
477 /// In particular, this routine gives user-defined conversion
478 /// sequences and ambiguous conversion sequences the same rank,
479 /// per C++ [over.best.ics]p10.
480 unsigned getKindRank() const {
482 case StandardConversion:
485 case UserDefinedConversion:
486 case AmbiguousConversion:
489 case EllipsisConversion:
496 llvm_unreachable("Invalid ImplicitConversionSequence::Kind!");
499 bool isBad() const { return getKind() == BadConversion; }
500 bool isStandard() const { return getKind() == StandardConversion; }
501 bool isEllipsis() const { return getKind() == EllipsisConversion; }
502 bool isAmbiguous() const { return getKind() == AmbiguousConversion; }
503 bool isUserDefined() const { return getKind() == UserDefinedConversion; }
504 bool isFailure() const { return isBad() || isAmbiguous(); }
506 /// Determines whether this conversion sequence has been
507 /// initialized. Most operations should never need to query
508 /// uninitialized conversions and should assert as above.
509 bool isInitialized() const { return ConversionKind != Uninitialized; }
511 /// Sets this sequence as a bad conversion for an explicit argument.
512 void setBad(BadConversionSequence::FailureKind Failure,
513 Expr *FromExpr, QualType ToType) {
514 setKind(BadConversion);
515 Bad.init(Failure, FromExpr, ToType);
518 /// Sets this sequence as a bad conversion for an implicit argument.
519 void setBad(BadConversionSequence::FailureKind Failure,
520 QualType FromType, QualType ToType) {
521 setKind(BadConversion);
522 Bad.init(Failure, FromType, ToType);
525 void setStandard() { setKind(StandardConversion); }
526 void setEllipsis() { setKind(EllipsisConversion); }
527 void setUserDefined() { setKind(UserDefinedConversion); }
528 void setAmbiguous() {
529 if (ConversionKind == AmbiguousConversion) return;
530 ConversionKind = AmbiguousConversion;
531 Ambiguous.construct();
534 /// \brief Whether the target is really a std::initializer_list, and the
535 /// sequence only represents the worst element conversion.
536 bool isStdInitializerListElement() const {
537 return StdInitializerListElement;
540 void setStdInitializerListElement(bool V = true) {
541 StdInitializerListElement = V;
544 // The result of a comparison between implicit conversion
545 // sequences. Use Sema::CompareImplicitConversionSequences to
546 // actually perform the comparison.
549 Indistinguishable = 0,
553 void DiagnoseAmbiguousConversion(Sema &S,
554 SourceLocation CaretLoc,
555 const PartialDiagnostic &PDiag) const;
560 enum OverloadFailureKind {
561 ovl_fail_too_many_arguments,
562 ovl_fail_too_few_arguments,
563 ovl_fail_bad_conversion,
564 ovl_fail_bad_deduction,
566 /// This conversion candidate was not considered because it
567 /// duplicates the work of a trivial or derived-to-base
569 ovl_fail_trivial_conversion,
571 /// This conversion candidate is not viable because its result
572 /// type is not implicitly convertible to the desired type.
573 ovl_fail_bad_final_conversion,
575 /// This conversion function template specialization candidate is not
576 /// viable because the final conversion was not an exact match.
577 ovl_fail_final_conversion_not_exact,
579 /// (CUDA) This candidate was not viable because the callee
580 /// was not accessible from the caller's target (i.e. host->device,
581 /// global->host, device->host).
585 /// OverloadCandidate - A single candidate in an overload set (C++ 13.3).
586 struct OverloadCandidate {
587 /// Function - The actual function that this candidate
588 /// represents. When NULL, this is a built-in candidate
589 /// (C++ [over.oper]) or a surrogate for a conversion to a
590 /// function pointer or reference (C++ [over.call.object]).
591 FunctionDecl *Function;
593 /// FoundDecl - The original declaration that was looked up /
594 /// invented / otherwise found, together with its access.
595 /// Might be a UsingShadowDecl or a FunctionTemplateDecl.
596 DeclAccessPair FoundDecl;
598 // BuiltinTypes - Provides the return and parameter types of a
599 // built-in overload candidate. Only valid when Function is NULL.
602 QualType ParamTypes[3];
605 /// Surrogate - The conversion function for which this candidate
606 /// is a surrogate, but only if IsSurrogate is true.
607 CXXConversionDecl *Surrogate;
609 /// Conversions - The conversion sequences used to convert the
610 /// function arguments to the function parameters, the pointer points to a
611 /// fixed size array with NumConversions elements. The memory is owned by
612 /// the OverloadCandidateSet.
613 ImplicitConversionSequence *Conversions;
615 /// The FixIt hints which can be used to fix the Bad candidate.
616 ConversionFixItGenerator Fix;
618 /// NumConversions - The number of elements in the Conversions array.
619 unsigned NumConversions;
621 /// Viable - True to indicate that this overload candidate is viable.
624 /// IsSurrogate - True to indicate that this candidate is a
625 /// surrogate for a conversion to a function pointer or reference
626 /// (C++ [over.call.object]).
629 /// IgnoreObjectArgument - True to indicate that the first
630 /// argument's conversion, which for this function represents the
631 /// implicit object argument, should be ignored. This will be true
632 /// when the candidate is a static member function (where the
633 /// implicit object argument is just a placeholder) or a
634 /// non-static member function when the call doesn't have an
636 bool IgnoreObjectArgument;
638 /// FailureKind - The reason why this candidate is not viable.
639 /// Actually an OverloadFailureKind.
640 unsigned char FailureKind;
642 /// \brief The number of call arguments that were explicitly provided,
643 /// to be used while performing partial ordering of function templates.
644 unsigned ExplicitCallArguments;
647 DeductionFailureInfo DeductionFailure;
649 /// FinalConversion - For a conversion function (where Function is
650 /// a CXXConversionDecl), the standard conversion that occurs
651 /// after the call to the overload candidate to convert the result
652 /// of calling the conversion function to the required type.
653 StandardConversionSequence FinalConversion;
656 /// hasAmbiguousConversion - Returns whether this overload
657 /// candidate requires an ambiguous conversion or not.
658 bool hasAmbiguousConversion() const {
659 for (unsigned i = 0, e = NumConversions; i != e; ++i) {
660 if (!Conversions[i].isInitialized()) return false;
661 if (Conversions[i].isAmbiguous()) return true;
666 bool TryToFixBadConversion(unsigned Idx, Sema &S) {
667 bool CanFix = Fix.tryToFixConversion(
668 Conversions[Idx].Bad.FromExpr,
669 Conversions[Idx].Bad.getFromType(),
670 Conversions[Idx].Bad.getToType(), S);
672 // If at least one conversion fails, the candidate cannot be fixed.
680 /// OverloadCandidateSet - A set of overload candidates, used in C++
681 /// overload resolution (C++ 13.3).
682 class OverloadCandidateSet {
683 SmallVector<OverloadCandidate, 16> Candidates;
684 llvm::SmallPtrSet<Decl *, 16> Functions;
686 // Allocator for OverloadCandidate::Conversions. We store the first few
687 // elements inline to avoid allocation for small sets.
688 llvm::BumpPtrAllocator ConversionSequenceAllocator;
692 unsigned NumInlineSequences;
693 char InlineSpace[16 * sizeof(ImplicitConversionSequence)];
695 OverloadCandidateSet(const OverloadCandidateSet &) LLVM_DELETED_FUNCTION;
696 void operator=(const OverloadCandidateSet &) LLVM_DELETED_FUNCTION;
698 void destroyCandidates();
701 OverloadCandidateSet(SourceLocation Loc) : Loc(Loc), NumInlineSequences(0){}
702 ~OverloadCandidateSet() { destroyCandidates(); }
704 SourceLocation getLocation() const { return Loc; }
706 /// \brief Determine when this overload candidate will be new to the
708 bool isNewCandidate(Decl *F) {
709 return Functions.insert(F->getCanonicalDecl());
712 /// \brief Clear out all of the candidates.
715 typedef SmallVectorImpl<OverloadCandidate>::iterator iterator;
716 iterator begin() { return Candidates.begin(); }
717 iterator end() { return Candidates.end(); }
719 size_t size() const { return Candidates.size(); }
720 bool empty() const { return Candidates.empty(); }
722 /// \brief Add a new candidate with NumConversions conversion sequence slots
723 /// to the overload set.
724 OverloadCandidate &addCandidate(unsigned NumConversions = 0) {
725 Candidates.push_back(OverloadCandidate());
726 OverloadCandidate &C = Candidates.back();
728 // Assign space from the inline array if there are enough free slots
730 if (NumConversions + NumInlineSequences <= 16) {
731 ImplicitConversionSequence *I =
732 (ImplicitConversionSequence*)InlineSpace;
733 C.Conversions = &I[NumInlineSequences];
734 NumInlineSequences += NumConversions;
736 // Otherwise get memory from the allocator.
737 C.Conversions = ConversionSequenceAllocator
738 .Allocate<ImplicitConversionSequence>(NumConversions);
741 // Construct the new objects.
742 for (unsigned i = 0; i != NumConversions; ++i)
743 new (&C.Conversions[i]) ImplicitConversionSequence();
745 C.NumConversions = NumConversions;
749 /// Find the best viable function on this overload set, if it exists.
750 OverloadingResult BestViableFunction(Sema &S, SourceLocation Loc,
751 OverloadCandidateSet::iterator& Best,
752 bool UserDefinedConversion = false);
754 void NoteCandidates(Sema &S,
755 OverloadCandidateDisplayKind OCD,
756 ArrayRef<Expr *> Args,
758 SourceLocation Loc = SourceLocation());
761 bool isBetterOverloadCandidate(Sema &S,
762 const OverloadCandidate& Cand1,
763 const OverloadCandidate& Cand2,
765 bool UserDefinedConversion = false);
766 } // end namespace clang
768 #endif // LLVM_CLANG_SEMA_OVERLOAD_H