mariadb/include/template_utils.h
Aleksey Midenkov fc7da4dd4f IB, SQL: InnoDB partitioning [closes #118]
* native InnoDB partitioning for BY SYSTEM_TIME partitions.
2017-05-05 20:36:28 +03:00

98 lines
2.8 KiB
C++

/* Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
#ifndef TEMPLATE_UTILS_INCLUDED
#define TEMPLATE_UTILS_INCLUDED
/**
Clears a container, but deletes all objects that the elements point to first.
@tparam Container of pointers.
*/
template<typename Container_type>
void delete_container_pointers(Container_type &container)
{
typename Container_type::iterator it1= container.begin();
typename Container_type::iterator it2= container.end();
for (; it1 != it2; ++it1)
{
delete (*it1);
}
container.clear();
}
/**
Clears a container, but frees all objects that the elements point to first.
@tparam Container of pointers.
*/
template<typename Container_type>
void my_free_container_pointers(Container_type &container)
{
typename Container_type::iterator it1= container.begin();
typename Container_type::iterator it2= container.end();
for (; it1 != it2; ++it1)
{
my_free(*it1);
}
container.clear();
}
/**
Casts from one pointer type, to another, without using
reinterpret_cast or C-style cast:
foo *f; bar *b= pointer_cast<bar*>(f);
This avoids having to do:
foo *f; bar *b= static_cast<b*>(static_cast<void*>(f));
*/
template<typename T>
inline T pointer_cast(void *p)
{
return static_cast<T>(p);
}
template<typename T>
inline const T pointer_cast(const void *p)
{
return static_cast<const T>(p);
}
/**
Casts from one pointer type to another in a type hierarchy.
In debug mode, we verify the cast is indeed legal.
*/
template<typename Target, typename Source>
inline Target down_cast(Source arg)
{
DBUG_ASSERT(NULL != dynamic_cast<Target>(arg));
return static_cast<Target>(arg);
}
/**
Sometimes the compiler insists that types be the same and does not do any
implicit conversion. For example:
Derived1 *a;
Derived2 *b; // Derived1 and 2 are children classes of Base
Base *x= cond ? a : b; // Error, need to force a cast.
Use:
Base *x= cond ? implicit_cast<Base*>(a) : implicit_cast<Base*>(b);
static_cast would work too, but would be less safe (allows any
pointer-to-pointer conversion, not only up-casts).
*/
template<typename To>
inline To implicit_cast(To x) { return x; }
#endif // TEMPLATE_UTILS_INCLUDED