Component bslmf_removecv [Package bslmf]

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

Classes
struct	bsl::remove_cv< t_TYPE >

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Detailed Description

Outline

• Purpose
• Classes
• Description
  • Usage
    • Example 1: Removing the CV-Qualifiers of a Type

Purpose:

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

Classes:

bsl::remove_cv	meta-function for removing top-level cv-qualifiers
bsl::remove_cv_t	alias to the return type of the meta-function

See also:

Component bslmf_addcv

Description:

This component defines a meta-function, bsl::remove_cv, and declares a bsl::remove_cv_t alias to the return type of the bsl::remove_cv, that may be used to remove any top-level cv-qualifiers (const-qualifier and volatile-qualifier) from a type.

bsl::remove_cv and bsl::remove_cv_t meet the requirements of the remove_cv template defined in the C++11 standard [meta.trans.cv].

Usage:

In this section we show intended use of this component.

Example 1: Removing the CV-Qualifiers of a Type:

Suppose that we want to remove the cv-qualifiers from a particular type.

First, we create two typedefs -- a const-qualified and volatile-qualified type (MyCvType) and the same type without the cv-qualifiers (MyType):

  typedef int                MyType;
  typedef const volatile int MyCvType;

Now, we remove the cv-qualifiers from MyCvType using bsl::remove_cv and verify that the resulting type is the same as MyType:

  assert(true == (bsl::is_same<bsl::remove_cv<MyCvType>::type,
                                                            MyType>::value));

Finally, if the current compiler supports alias templates C++11 feature, we remove a const-qualified and volatile-qualifier from MyCvType using bsl::remove_cv_t and verify that the resulting type is the same as MyType:

#ifdef BSLS_COMPILERFEATURES_SUPPORT_ALIAS_TEMPLATES
  assert(true ==
                  (bsl::is_same<bsl::remove_cv_t<MyCvType>, MyType>::value));
#endif

Note, that the bsl::remove_cv_t avoids the ::type suffix and typename prefix when we want to use the result of the bsl::remove_cv meta-function in templates.