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      1 //===- TemplateDeduction.h - C++ template argument deduction ----*- C++ -*-===/
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //===----------------------------------------------------------------------===/
      8 //
      9 //  This file provides types used with Sema's template argument deduction
     10 // routines.
     11 //
     12 //===----------------------------------------------------------------------===/
     13 #ifndef LLVM_CLANG_SEMA_TEMPLATE_DEDUCTION_H
     14 #define LLVM_CLANG_SEMA_TEMPLATE_DEDUCTION_H
     15 
     16 #include "clang/Basic/PartialDiagnostic.h"
     17 #include "clang/AST/DeclTemplate.h"
     18 #include "llvm/ADT/SmallVector.h"
     19 
     20 namespace clang {
     21 
     22 class ASTContext;
     23 class TemplateArgumentList;
     24 
     25 namespace sema {
     26 
     27 /// \brief Provides information about an attempted template argument
     28 /// deduction, whose success or failure was described by a
     29 /// TemplateDeductionResult value.
     30 class TemplateDeductionInfo {
     31   /// \brief The context in which the template arguments are stored.
     32   ASTContext &Context;
     33 
     34   /// \brief The deduced template argument list.
     35   ///
     36   TemplateArgumentList *Deduced;
     37 
     38   /// \brief The source location at which template argument
     39   /// deduction is occurring.
     40   SourceLocation Loc;
     41 
     42   /// \brief Warnings (and follow-on notes) that were suppressed due to
     43   /// SFINAE while performing template argument deduction.
     44   SmallVector<PartialDiagnosticAt, 4> SuppressedDiagnostics;
     45 
     46   // do not implement these
     47   TemplateDeductionInfo(const TemplateDeductionInfo&);
     48   TemplateDeductionInfo &operator=(const TemplateDeductionInfo&);
     49 
     50 public:
     51   TemplateDeductionInfo(ASTContext &Context, SourceLocation Loc)
     52     : Context(Context), Deduced(0), Loc(Loc) { }
     53 
     54   ~TemplateDeductionInfo() {
     55     // FIXME: if (Deduced) Deduced->Destroy(Context);
     56   }
     57 
     58   /// \brief Returns the location at which template argument is
     59   /// occurring.
     60   SourceLocation getLocation() const {
     61     return Loc;
     62   }
     63 
     64   /// \brief Take ownership of the deduced template argument list.
     65   TemplateArgumentList *take() {
     66     TemplateArgumentList *Result = Deduced;
     67     Deduced = 0;
     68     return Result;
     69   }
     70 
     71   /// \brief Provide a new template argument list that contains the
     72   /// results of template argument deduction.
     73   void reset(TemplateArgumentList *NewDeduced) {
     74     // FIXME: if (Deduced) Deduced->Destroy(Context);
     75     Deduced = NewDeduced;
     76   }
     77 
     78   /// \brief Add a new diagnostic to the set of diagnostics
     79   void addSuppressedDiagnostic(SourceLocation Loc,
     80                                const PartialDiagnostic &PD) {
     81     SuppressedDiagnostics.push_back(std::make_pair(Loc, PD));
     82   }
     83 
     84   /// \brief Iterator over the set of suppressed diagnostics.
     85   typedef SmallVectorImpl<PartialDiagnosticAt>::const_iterator
     86     diag_iterator;
     87 
     88   /// \brief Returns an iterator at the beginning of the sequence of suppressed
     89   /// diagnostics.
     90   diag_iterator diag_begin() const { return SuppressedDiagnostics.begin(); }
     91 
     92   /// \brief Returns an iterator at the end of the sequence of suppressed
     93   /// diagnostics.
     94   diag_iterator diag_end() const { return SuppressedDiagnostics.end(); }
     95 
     96   /// \brief The template parameter to which a template argument
     97   /// deduction failure refers.
     98   ///
     99   /// Depending on the result of template argument deduction, this
    100   /// template parameter may have different meanings:
    101   ///
    102   ///   TDK_Incomplete: this is the first template parameter whose
    103   ///   corresponding template argument was not deduced.
    104   ///
    105   ///   TDK_Inconsistent: this is the template parameter for which
    106   ///   two different template argument values were deduced.
    107   TemplateParameter Param;
    108 
    109   /// \brief The first template argument to which the template
    110   /// argument deduction failure refers.
    111   ///
    112   /// Depending on the result of the template argument deduction,
    113   /// this template argument may have different meanings:
    114   ///
    115   ///   TDK_Inconsistent: this argument is the first value deduced
    116   ///   for the corresponding template parameter.
    117   ///
    118   ///   TDK_SubstitutionFailure: this argument is the template
    119   ///   argument we were instantiating when we encountered an error.
    120   ///
    121   ///   TDK_NonDeducedMismatch: this is the template argument
    122   ///   provided in the source code.
    123   TemplateArgument FirstArg;
    124 
    125   /// \brief The second template argument to which the template
    126   /// argument deduction failure refers.
    127   ///
    128   /// FIXME: Finish documenting this.
    129   TemplateArgument SecondArg;
    130 };
    131 
    132 }
    133 }
    134 
    135 #endif
    136