freebsd-dev/contrib/libstdc++/stl/stl_tempbuf.h
1999-10-04 08:12:38 +00:00

124 lines
3.3 KiB
C++

/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/* NOTE: This is an internal header file, included by other STL headers.
* You should not attempt to use it directly.
*/
#ifndef __SGI_STL_INTERNAL_TEMPBUF_H
#define __SGI_STL_INTERNAL_TEMPBUF_H
__STL_BEGIN_NAMESPACE
template <class T>
pair<T*, ptrdiff_t> get_temporary_buffer(ptrdiff_t len, T*) {
if (len > ptrdiff_t(INT_MAX / sizeof(T)))
len = INT_MAX / sizeof(T);
while (len > 0) {
T* tmp = (T*) malloc((size_t)len * sizeof(T));
if (tmp != 0)
return pair<T*, ptrdiff_t>(tmp, len);
len /= 2;
}
return pair<T*, ptrdiff_t>((T*)0, 0);
}
template <class T>
void return_temporary_buffer(T* p) {
free(p);
}
template <class ForwardIterator,
class T
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
= iterator_traits<ForwardIterator>::value_type
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
>
class temporary_buffer {
private:
ptrdiff_t original_len;
ptrdiff_t len;
T* buffer;
void allocate_buffer() {
original_len = len;
buffer = 0;
if (len > (ptrdiff_t)(INT_MAX / sizeof(T)))
len = INT_MAX / sizeof(T);
while (len > 0) {
buffer = (T*) malloc(len * sizeof(T));
if (buffer)
break;
len /= 2;
}
}
void initialize_buffer(const T&, __true_type) {}
void initialize_buffer(const T& val, __false_type) {
uninitialized_fill_n(buffer, len, val);
}
public:
ptrdiff_t size() const { return len; }
ptrdiff_t requested_size() const { return original_len; }
T* begin() { return buffer; }
T* end() { return buffer + len; }
temporary_buffer(ForwardIterator first, ForwardIterator last) {
__STL_TRY {
len = 0;
distance(first, last, len);
allocate_buffer();
if (len > 0)
initialize_buffer(*first,
typename __type_traits<T>::has_trivial_default_constructor());
}
__STL_UNWIND(free(buffer); buffer = 0; len = 0);
}
~temporary_buffer() {
destroy(buffer, buffer + len);
free(buffer);
}
private:
temporary_buffer(const temporary_buffer&) {}
void operator=(const temporary_buffer&) {}
};
__STL_END_NAMESPACE
#endif /* __SGI_STL_INTERNAL_TEMPBUF_H */
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// mode:C++
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