Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
template <class T>
struct has_trivial_destructor : public true_type-or-false_type {};
Inherits: If T is a (possibly cv-qualified) type with a trivial destructor then inherits from true_type, otherwise inherits from false_type.
If a type has a trivial destructor then the destructor has no effect: calls to the destructor can be safely omitted. Note that using meta-programming to omit a call to a single trivial-constructor call is of no benefit whatsoever. However, if loops and/or exception handling code can also be omitted, then some benefit in terms of code size and speed can be obtained.
Compiler Compatibility: If the compiler does not support partial-specialization of class templates, then this template can not be used with function types.
Without some (as yet unspecified) help from the compiler, has_trivial_destructor will never report that a user-defined class or struct has a trivial destructor; this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have the necessary compiler intrinsics to detect user-defined classes with trivial constructors.
C++ Standard Reference: 12.4p3.
Header: #include
<boost/type_traits/has_trivial_destructor.hpp>
or #include <boost/type_traits.hpp>
Examples:
has_trivial_destructor<int>inherits fromtrue_type.
has_trivial_destructor<char*>::typeis the typetrue_type.
has_trivial_destructor<int (*)(long)>::valueis an integral constant expression that evaluates to true.
has_trivial_destructor<MyClass>::valueis an integral constant expression that evaluates to false.
has_trivial_destructor<T>::value_typeis the typebool.