bslmf Package

Provide meta-function versions of useful coding constructs. More...

Components
	Component bslmf_addconst
	Provide a meta-function for adding a top-level `const`-qualifier.
	Component bslmf_addcv
	Provide a meta-function for adding top-level cv-qualifiers.
	Component bslmf_addlvaluereference
	Provide a compile-time type transformation to lvalue reference.
	Component bslmf_addpointer
	Provide meta-function to transform a type to pointer to that type.
	Component bslmf_addreference
	Provide a meta-function for adding "reference-ness" to a type.
	Component bslmf_addrvaluereference
	Provide a compile-time type transformation to rvalue reference.
	Component bslmf_addvolatile
	Provide a meta-function for adding a `volatile`-qualifier.
	Component bslmf_allocatorargt
	Provide a tag type to precede allocator arguments.
	Component bslmf_arraytopointer
	Provide a meta-function to convert array types to pointer types.
	Component bslmf_assert
	Provide a compile-time assertion facility.
	Component bslmf_conditional
	Provide a compile-time conditional type selector.
	Component bslmf_decay
	Convert a type to the type used for pass-by-value.
	Component bslmf_detectnestedtrait
	Provide a facility for defining traits and detecting legacy traits.
	Component bslmf_enableif
	Provide a utility to set up SFINAE conditions in type deduction.
	Component bslmf_forwardingreftype
	Provide a meta-function for determining a forwarding type.
	Component bslmf_forwardingtype
	Provide a meta-function for determining an optimal forwarding type.
	Component bslmf_functionpointertraits
	Provide a meta-function for determining function pointer traits.
	Component bslmf_functionpointertraits_cpp03: PRIVATE
	Provide C++03 implementation for bslmf_functionpointertraits.h.
	Component bslmf_haspointersemantics
	Provide a type trait for pointer semantics.
	Component bslmf_if: DEPRECATED
	Provide a compile-time `if/else` (conditional) meta-function.
	Component bslmf_integersequence
	Provide a template parameter pack of integers.
	Component bslmf_integralconstant
	Provide a mapping from integral constants to unique types.
	Component bslmf_invokeresult
	Determine the result type of an invocable expression.
	Component bslmf_invokeresult_cpp03: PRIVATE
	Provide C++03 implementation for bslmf_invokeresult.h.
	Component bslmf_isaccessiblebaseof
	Provide a compile-time check for derived classes.
	Component bslmf_isarithmetic
	Provide a compile-time check for determining arithmetic types.
	Component bslmf_isarray
	Provide a compile-time check for array types.
	Component bslmf_isbitwiseequalitycomparable
	Provide a type trait for bitwise equality.
	Component bslmf_isbitwisemoveable
	Provide a primitive type trait for bitwise moveable classes.
	Component bslmf_isclass
	Provide a compile-time check for determining class types.
	Component bslmf_isconst
	Provide a compile-time check for `const`-qualified types.
	Component bslmf_isconvertible
	Provide a compile-time check for type conversion.
	Component bslmf_isconvertibletoany
	Provide a compile-time check for types convertible to any type.
	Component bslmf_iscopyconstructible
	Provide a meta-function to report if a type is copy constructible.
	Component bslmf_isempty
	Provide a compile-time check for detecting an empty class type.
	Component bslmf_isenum
	Provide compile-time check for determining enumerated types.
	Component bslmf_isfloatingpoint
	Provide a compile-time check for floating-point types.
	Component bslmf_isfunction
	Provide a compile-time check for determining function types.
	Component bslmf_isfundamental
	Provide a compile-time check for determining fundamental types.
	Component bslmf_isintegral
	Provide a compile-time check for integral types.
	Component bslmf_islvaluereference
	Provide a compile-time check for lvalue reference types.
	Component bslmf_ismemberfunctionpointer
	Provide a compile-time check for member function pointer types.
	Component bslmf_ismemberobjectpointer
	Provide a compile-time check for member object pointer types.
	Component bslmf_ismemberpointer
	Provide a compile-time check for non-static member pointer types.
	Component bslmf_isnothrowmoveconstructible
	Provide metafunction to identify no-throw move-constructible types.
	Component bslmf_isnothrowswappable
	Provide metafunction to identify nothrow swappable types.
	Component bslmf_ispair
	Provide a compile-time check for the bsl::pair type.
	Component bslmf_ispointer
	Provide a compile-time check for pointer types.
	Component bslmf_ispolymorphic
	Provide a compile-time check for determining polymorphic types.
	Component bslmf_isreference
	Provide a meta-function to test reference types.
	Component bslmf_isreferencewrapper
	Provide a trait to detect reference-wrapper specializations.
	Component bslmf_isrvaluereference
	Provide a compile-time check for rvalue reference types.
	Component bslmf_issame
	Provide a meta-function for testing if two types are the same.
	Component bslmf_isswappable
	Provide metafunction to identify swappable types.
	Component bslmf_istransparentpredicate
	Support detection of whether a predicate functor is transparent.
	Component bslmf_istriviallycopyable
	Provide a meta-function for determining trivially copyable types.
	Component bslmf_istriviallydefaultconstructible
	Provide a compile-time check for trivially default-constructible.
	Component bslmf_isvoid
	Provide a compile-time check for `void` types.
	Component bslmf_isvolatile
	Provide a compile-time check for `volatile`-qualified types.
	Component bslmf_makeintegersequence
	Provide a template parameter pack of integers.
	Component bslmf_matchanytype
	Provide a generic type to which any type can be converted.
	Component bslmf_matcharithmetictype
	Provide a class supporting "do-the-right-thing clause" dispatch.
	Component bslmf_memberfunctionpointertraits
	Provide meta-functions to detect member function pointer traits.
	Component bslmf_memberpointertraits
	Provide meta-function to detect pointer to member traits.
	Component bslmf_metaint: DEPRECATED
	Provide a meta-function to map integral constants to unique types.
	Component bslmf_movableref
	Provide a vocabulary type to enable move semantics.
	Component bslmf_nestedtraitdeclaration
	Provide a nested declaration to associate a class with a trait.
	Component bslmf_nil
	Provide a nil type.
	Component bslmf_nthparameter
	Metafunction to return the Nth type parameter in a parameter pack.
	Component bslmf_nthparameter_cpp03: PRIVATE
	Provide C++03 implementation for bslmf_nthparameter.h.
	Component bslmf_removeconst
	Provide a meta-function for removing top-level `const`-qualifier.
	Component bslmf_removecv
	Provide a meta-function for removing top-level cv-qualifiers.
	Component bslmf_removecvq
	Provide a meta-function for removing `const`/`volatile` qualifiers.
	Component bslmf_removecvref
	Provide a meta-func for removing reference-ness and cv-qualifiers.
	Component bslmf_removeextent
	Provide a metafunction to return an array type's element type.
	Component bslmf_removepointer
	Provide a meta-function to transform pointer type to referent type.
	Component bslmf_removereference
	Provide a meta-function for stripping reference-ness from types.
	Component bslmf_removevolatile
	Provide a meta-function for removing `volatile`-qualifier.
	Component bslmf_resulttype
	Provide access to `result_type` or `ResultType` nested type.
	Component bslmf_selecttrait
	Provide clean compile-time dispatch based on multiple traits.
	Component bslmf_switch
	Provide a compile-time `switch` meta-function.
	Component bslmf_tag
	Provide an integral-constant-to-type conversion.
	Component bslmf_typeidentity
	Provide a template metafunction that returns its argument.
	Component bslmf_typelist
	Provide a typelist component.
	Component bslmf_usesallocator
	Provide a meta-function to determine if a type uses an allocator.
	Component bslmf_usesallocatorargt
	Provide a metafunction for `allocator_arg_t` construction.
	Component bslmf_util
	Provide low-level functions on `bslmf` types.
	Component bslmf_voidtype
	Provide a helper for implementing SFINAE-based metafunctions.

Detailed Description

Outline

Purpose
MNEMONIC: Basic Standard Library Meta-Functions (bslmf)
Description
- Hierarchical Synopsis
- Component Synopsis

Purpose:: Provide meta-function versions of useful coding constructs.

MNEMONIC: Basic Standard Library Meta-Functions (bslmf):

Description:: The bslmf package provides meta-function equivalents of certain useful coding constructs. A meta-function is a template-based, compile-time construct that behaves like a (runtime) function in that it "evaluates" arguments and does something different based on the input it is passed (in the case of templates, the input it is instantiated with). bslmf provides metafunctions to evaluate (at compile time) constructs such as the following: an if-statement equivalent, whether a (template) argument is a fundamental type, whether an argument is an enum type, whether two arguments have the same type, and more.

The "return value" of that function is generally a compile-time constant under the form of a nested enum VALUE, or in some cases a nested Type, or both. For instance, in order to evaluate whether two types are the same, one could write a meta-function predicate (evaluating to 0 or 1) as follows:

  template <class U, class V>
  struct IsSame {
      // This 'struct' provides a meta function parameterized by two types 'U'
      // and 'V', that takes 'VALUE == 0' unless 'U' and 'V' are the same type,
      // in which case it takes 'VALUE == 1'.

      // PUBLIC TYPES
      enum { VALUE = 0 };
      typedef bslmf_MetaInt<VALUE>  Type;
  };

  // SPECIALIZATIONS
  template <class T>
  struct IsSame<T, T> {
      // This specialization of the 'IsSame' meta function is parameterized by
      // a single type 'T' and is selected if the two parameters of 'IsSame',
      // 'U' and 'V', are both equal to 'T'.  It takes 'VALUE == 1'.

      // PUBLIC TYPES
      enum { VALUE = 1 };
      typedef bslmf_MetaInt<VALUE>  Type;
  };

Note the use of a bslmf_MetaInt nested type usually employed for function dispatching. See the bslmf_issame component-level documentation for a more thorough usage example.

: Other meta-functions don't have a VALUE, but apply some type of transformation (e.g., removing top-level const qualifiers, decaying array and function types to pointer types). Those usually have a nested Type.

Hierarchical Synopsis:

The bslmf package currently has 88 components having 21 levels of physical dependency. The list below shows the hierarchical ordering of the components. The order of components within each level is not architecturally significant, just alphabetical.

  21. bslmf_isnothrowswappable

  20. bslmf_isswappable

  19. bslmf_forwardingreftype
      bslmf_forwardingtype
      bslmf_invokeresult
      bslmf_util

  18. bslmf_movableref

  17. bslmf_isbitwisemoveable
      bslmf_iscopyconstructible
      bslmf_isnothrowmoveconstructible

  16. bslmf_haspointersemantics
      bslmf_isbitwiseequalitycomparable
      bslmf_istriviallycopyable
      bslmf_istriviallydefaultconstructible
      bslmf_matcharithmetictype
      bslmf_usesallocatorargt

  15. bslmf_detectnestedtrait
      bslmf_isenum

  14. bslmf_isaccessiblebaseof
      bslmf_isconvertibletoany
      bslmf_nestedtraitdeclaration
      bslmf_usesallocator

  13. bslmf_isconvertible

  12. bslmf_enableif

  11. bslmf_isfundamental

  10. bslmf_isarithmetic

   9. bslmf_isintegral
      bslmf_ismemberpointer

   8. bslmf_addcv
      bslmf_ismemberobjectpointer

   7. bslmf_addconst
      bslmf_addvolatile
      bslmf_decay
      bslmf_isempty
      bslmf_ismemberfunctionpointer
      bslmf_ispolymorphic
      bslmf_removepointer

   6. bslmf_isclass
      bslmf_isfloatingpoint
      bslmf_isfunction
      bslmf_ispointer
      bslmf_isvoid
      bslmf_memberfunctionpointertraits
      bslmf_memberpointertraits
      bslmf_removecvq
      bslmf_removecvref

   5. bslmf_addpointer
      bslmf_addreference
      bslmf_functionpointertraits
      bslmf_if                                           !DEPRECATED!
      bslmf_makeintegersequence
      bslmf_matchanytype
      bslmf_removecv
      bslmf_selecttrait

   4. bslmf_addlvaluereference
      bslmf_addrvaluereference
      bslmf_arraytopointer
      bslmf_conditional
      bslmf_integersequence
      bslmf_isconst
      bslmf_isreference
      bslmf_isvolatile
      bslmf_metaint                                      !DEPRECATED!
      bslmf_nthparameter
      bslmf_removeconst
      bslmf_removeextent
      bslmf_removereference
      bslmf_removevolatile
      bslmf_resulttype
      bslmf_switch
      bslmf_typeidentity
      bslmf_typelist

   3. bslmf_isarray
      bslmf_islvaluereference
      bslmf_ispair
      bslmf_isreferencewrapper
      bslmf_isrvaluereference
      bslmf_issame
      bslmf_istransparentpredicate
      bslmf_nil
      bslmf_tag

   2. bslmf_allocatorargt
      bslmf_assert
      bslmf_integralconstant
      bslmf_voidtype

   1. bslmf_functionpointertraits_cpp03                               !PRIVATE!
      bslmf_invokeresult_cpp03                                        !PRIVATE!
      bslmf_nthparameter_cpp03                                        !PRIVATE!

Component Synopsis:

: bslmf_addconst:
Provide a meta-function for adding a top-level const-qualifier.

: bslmf_addcv:
Provide a meta-function for adding top-level cv-qualifiers.

: bslmf_addlvaluereference:
Provide a compile-time type transformation to lvalue reference.

: bslmf_addpointer:
Provide meta-function to transform a type to pointer to that type.

: bslmf_addreference:
Provide a meta-function for adding "reference-ness" to a type.

: bslmf_addrvaluereference:
Provide a compile-time type transformation to rvalue reference.

: bslmf_addvolatile:
Provide a meta-function for adding a volatile-qualifier.

: bslmf_allocatorargt:
Provide a tag type to precede allocator arguments.

: bslmf_arraytopointer:
Provide a meta-function to convert array types to pointer types.

: bslmf_assert:
Provide a compile-time assertion facility.

: bslmf_conditional:
Provide a compile-time conditional type selector.

: bslmf_decay:
Convert a type to the type used for pass-by-value.

: bslmf_detectnestedtrait:
Provide a facility for defining traits and detecting legacy traits.

: bslmf_enableif:
Provide a utility to set up SFINAE conditions in type deduction.

: bslmf_forwardingreftype:
Provide a meta-function for determining a forwarding type.

: bslmf_forwardingtype:
Provide a meta-function for determining an optimal forwarding type.

: bslmf_functionpointertraits:
Provide a meta-function for determining function pointer traits.

: bslmf_functionpointertraits_cpp03: PRIVATE
Provide C++03 implementation for bslmf_functionpointertraits.h

: bslmf_haspointersemantics:
Provide a type trait for pointer semantics.

: bslmf_if: DEPRECATED
Provide a compile-time if/else (conditional) meta-function.

: bslmf_integersequence:
Provide a template parameter pack of integers.

: bslmf_integralconstant:
Provide a mapping from integral constants to unique types.

: bslmf_invokeresult:
Determine the result type of an invocable expression.

: bslmf_invokeresult_cpp03: PRIVATE
Provide C++03 implementation for bslmf_invokeresult.h

: bslmf_isaccessiblebaseof:
Provide a compile-time check for derived classes.

: bslmf_isarithmetic:
Provide a compile-time check for determining arithmetic types.

: bslmf_isarray:
Provide a compile-time check for array types.

: bslmf_isbitwiseequalitycomparable:
Provide a type trait for bitwise equality.

: bslmf_isbitwisemoveable:
Provide a primitive type trait for bitwise moveable classes.

: bslmf_isclass:
Provide a compile-time check for determining class types.

: bslmf_isconst:
Provide a compile-time check for const-qualified types.

: bslmf_isconvertible:
Provide a compile-time check for type conversion.

: bslmf_isconvertibletoany:
Provide a compile-time check for types convertible to any type.

: bslmf_iscopyconstructible:
Provide a meta-function to report if a type is copy constructible.

: bslmf_isempty:
Provide a compile-time check for detecting an empty class type.

: bslmf_isenum:
Provide compile-time check for determining enumerated types.

: bslmf_isfloatingpoint:
Provide a compile-time check for floating-point types.

: bslmf_isfunction:
Provide a compile-time check for determining function types.

: bslmf_isfundamental:
Provide a compile-time check for determining fundamental types.

: bslmf_isintegral:
Provide a compile-time check for integral types.

: bslmf_islvaluereference:
Provide a compile-time check for lvalue reference types.

: bslmf_ismemberfunctionpointer:
Provide a compile-time check for member function pointer types.

: bslmf_ismemberobjectpointer:
Provide a compile-time check for member object pointer types.

: bslmf_ismemberpointer:
Provide a compile-time check for non-static member pointer types.

: bslmf_isnothrowmoveconstructible:
Provide metafunction to identify no-throw move-constructible types.

: bslmf_isnothrowswappable:
Provide metafunction to identify nothrow swappable types.

: bslmf_ispair:
Provide a compile-time check for the bsl::pair type.

: bslmf_ispointer:
Provide a compile-time check for pointer types.

: bslmf_ispolymorphic:
Provide a compile-time check for determining polymorphic types.

: bslmf_isreference:
Provide a meta-function to test reference types.

: bslmf_isreferencewrapper:
Provide a trait to detect reference-wrapper specializations.

: bslmf_isrvaluereference:
Provide a compile-time check for rvalue reference types.

: bslmf_issame:
Provide a meta-function for testing if two types are the same.

: bslmf_isswappable:
Provide metafunction to identify swappable types.

: bslmf_istransparentpredicate:
Support detection of whether a predicate functor is transparent.

: bslmf_istriviallycopyable:
Provide a meta-function for determining trivially copyable types.

: bslmf_istriviallydefaultconstructible:
Provide a compile-time check for trivially default-constructible.

: bslmf_isvoid:
Provide a compile-time check for void types.

: bslmf_isvolatile:
Provide a compile-time check for volatile-qualified types.

: bslmf_makeintegersequence:
Provide a template parameter pack of integers.

: bslmf_matchanytype:
Provide a generic type to which any type can be converted.

: bslmf_matcharithmetictype:
Provide a class supporting "do-the-right-thing clause" dispatch.

: bslmf_memberfunctionpointertraits:
Provide meta-functions to detect member function pointer traits.

: bslmf_memberpointertraits:
Provide meta-function to detect pointer to member traits.

: bslmf_metaint: DEPRECATED
Provide a meta-function to map integral constants to unique types.

: bslmf_movableref:
Provide a vocabulary type to enable move semantics.

: bslmf_nestedtraitdeclaration:
Provide a nested declaration to associate a class with a trait.

: bslmf_nil:
Provide a nil type.

: bslmf_nthparameter:
Metafunction to return the Nth type parameter in a parameter pack

: bslmf_nthparameter_cpp03: PRIVATE
Provide C++03 implementation for bslmf_nthparameter.h

: bslmf_removeconst:
Provide a meta-function for removing top-level const-qualifier.

: bslmf_removecv:
Provide a meta-function for removing top-level cv-qualifiers.

: bslmf_removecvq:
Provide a meta-function for removing const/volatile qualifiers.

: bslmf_removecvref:
Provide a meta-func for removing reference-ness and cv-qualifiers.

: bslmf_removeextent:
Provide a metafunction to return an array type's element type.

: bslmf_removepointer:
Provide a meta-function to transform pointer type to referent type.

: bslmf_removereference:
Provide a meta-function for stripping reference-ness from types.

: bslmf_removevolatile:
Provide a meta-function for removing volatile-qualifier.

: bslmf_resulttype:
Provide access to result_type or ResultType nested type.

: bslmf_selecttrait:
Provide clean compile-time dispatch based on multiple traits

: bslmf_switch:
Provide a compile-time switch meta-function.

: bslmf_tag:
Provide an integral-constant-to-type conversion.

: bslmf_typeidentity:
Provide a template metafunction that returns its argument.

: bslmf_typelist:
Provide a typelist component.

: bslmf_usesallocator:
Provide a meta-function to determine if a type uses an allocator.

: bslmf_usesallocatorargt:
Provide a metafunction for allocator_arg_t construction

: bslmf_util:
Provide low-level functions on bslmf types.

: bslmf_voidtype:
Provide a helper for implementing SFINAE-based metafunctions.

Package bslmf [Package Group bsl]

Components

Detailed Description

Package bslmf
[Package Group bsl]