Diff: include/opencv2/core/cvstd.hpp

Revision:

0:0e0631af0305

diff -r 000000000000 -r 0e0631af0305 include/opencv2/core/cvstd.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/opencv2/core/cvstd.hpp	Fri Jan 29 04:53:38 2021 +0000
@@ -0,0 +1,1066 @@
+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+//  By downloading, copying, installing or using the software you agree to this license.
+//  If you do not agree to this license, do not download, install,
+//  copy or use the software.
+//
+//
+//                          License Agreement
+//                For Open Source Computer Vision Library
+//
+// Copyright (C) 2000-2008, Intel Corporation, all rights reserved.
+// Copyright (C) 2009, Willow Garage Inc., all rights reserved.
+// Copyright (C) 2013, OpenCV Foundation, all rights reserved.
+// Third party copyrights are property of their respective owners.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+//   * Redistribution's of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//
+//   * Redistribution's in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//
+//   * The name of the copyright holders may not be used to endorse or promote products
+//     derived from this software without specific prior written permission.
+//
+// This software is provided by the copyright holders and contributors "as is" and
+// any express or implied warranties, including, but not limited to, the implied
+// warranties of merchantability and fitness for a particular purpose are disclaimed.
+// In no event shall the Intel Corporation or contributors be liable for any direct,
+// indirect, incidental, special, exemplary, or consequential damages
+// (including, but not limited to, procurement of substitute goods or services;
+// loss of use, data, or profits; or business interruption) however caused
+// and on any theory of liability, whether in contract, strict liability,
+// or tort (including negligence or otherwise) arising in any way out of
+// the use of this software, even if advised of the possibility of such damage.
+//
+//M*/
+
+#ifndef OPENCV_CORE_CVSTD_HPP
+#define OPENCV_CORE_CVSTD_HPP
+
+#ifndef __cplusplus
+#  error cvstd.hpp header must be compiled as C++
+#endif
+
+#include "opencv2/core/cvdef.h"
+
+#include <cstddef>
+#include <cstring>
+#include <cctype>
+
+#ifndef OPENCV_NOSTL
+#  include <string>
+#endif
+
+// import useful primitives from stl
+#ifndef OPENCV_NOSTL_TRANSITIONAL
+#  include <algorithm>
+#  include <utility>
+#  include <cstdlib> //for abs(int)
+#  include <cmath>
+
+namespace cv
+{
+    static inline uchar abs(uchar a) { return a; }
+    static inline ushort abs(ushort a) { return a; }
+    static inline unsigned abs(unsigned a) { return a; }
+    static inline uint64 abs(uint64 a) { return a; }
+
+    using std::min;
+    using std::max;
+    using std::abs;
+    using std::swap;
+    using std::sqrt;
+    using std::exp;
+    using std::pow;
+    using std::log;
+}
+
+#else
+namespace cv
+{
+    template<typename T> static inline T min(T a, T b) { return a < b ? a : b; }
+    template<typename T> static inline T max(T a, T b) { return a > b ? a : b; }
+    template<typename T> static inline T abs(T a) { return a < 0 ? -a : a; }
+    template<typename T> static inline void swap(T& a, T& b) { T tmp = a; a = b; b = tmp; }
+
+    template<> inline uchar abs(uchar a) { return a; }
+    template<> inline ushort abs(ushort a) { return a; }
+    template<> inline unsigned abs(unsigned a) { return a; }
+    template<> inline uint64 abs(uint64 a) { return a; }
+}
+#endif
+
+namespace cv {
+
+//! @addtogroup core_utils
+//! @{
+
+//////////////////////////// memory management functions ////////////////////////////
+
+/** @brief Allocates an aligned memory buffer.
+
+The function allocates the buffer of the specified size and returns it. When the buffer size is 16
+bytes or more, the returned buffer is aligned to 16 bytes.
+@param bufSize Allocated buffer size.
+ */
+CV_EXPORTS void* fastMalloc(size_t bufSize);
+
+/** @brief Deallocates a memory buffer.
+
+The function deallocates the buffer allocated with fastMalloc . If NULL pointer is passed, the
+function does nothing. C version of the function clears the pointer *pptr* to avoid problems with
+double memory deallocation.
+@param ptr Pointer to the allocated buffer.
+ */
+CV_EXPORTS void fastFree(void* ptr);
+
+/*!
+  The STL-compilant memory Allocator based on cv::fastMalloc() and cv::fastFree()
+*/
+template<typename _Tp> class Allocator
+{
+public:
+    typedef _Tp value_type;
+    typedef value_type* pointer;
+    typedef const value_type* const_pointer;
+    typedef value_type& reference;
+    typedef const value_type& const_reference;
+    typedef size_t size_type;
+    typedef ptrdiff_t difference_type;
+    template<typename U> class rebind { typedef Allocator<U> other; };
+
+    explicit Allocator() {}
+    ~Allocator() {}
+    explicit Allocator(Allocator const&) {}
+    template<typename U>
+    explicit Allocator(Allocator<U> const&) {}
+
+    // address
+    pointer address(reference r) { return &r; }
+    const_pointer address(const_reference r) { return &r; }
+
+    pointer allocate(size_type count, const void* =0) { return reinterpret_cast<pointer>(fastMalloc(count * sizeof (_Tp))); }
+    void deallocate(pointer p, size_type) { fastFree(p); }
+
+    void construct(pointer p, const _Tp& v) { new(static_cast<void*>(p)) _Tp(v); }
+    void destroy(pointer p) { p->~_Tp(); }
+
+    size_type max_size() const { return cv::max(static_cast<_Tp>(-1)/sizeof(_Tp), 1); }
+};
+
+//! @} core_utils
+
+//! @cond IGNORED
+
+namespace detail
+{
+
+// Metafunction to avoid taking a reference to void.
+template<typename T>
+struct RefOrVoid { typedef T& type; };
+
+template<>
+struct RefOrVoid<void>{ typedef void type; };
+
+template<>
+struct RefOrVoid<const void>{ typedef const void type; };
+
+template<>
+struct RefOrVoid<volatile void>{ typedef volatile void type; };
+
+template<>
+struct RefOrVoid<const volatile void>{ typedef const volatile void type; };
+
+// This class would be private to Ptr, if it didn't have to be a non-template.
+struct PtrOwner;
+
+}
+
+template<typename Y>
+struct DefaultDeleter
+{
+    void operator () (Y* p) const;
+};
+
+//! @endcond
+
+//! @addtogroup core_basic
+//! @{
+
+/** @brief Template class for smart pointers with shared ownership
+
+A Ptr\<T\> pretends to be a pointer to an object of type T. Unlike an ordinary pointer, however, the
+object will be automatically cleaned up once all Ptr instances pointing to it are destroyed.
+
+Ptr is similar to boost::shared_ptr that is part of the Boost library
+(<http://www.boost.org/doc/libs/release/libs/smart_ptr/shared_ptr.htm>) and std::shared_ptr from
+the [C++11](http://en.wikipedia.org/wiki/C++11) standard.
+
+This class provides the following advantages:
+-   Default constructor, copy constructor, and assignment operator for an arbitrary C++ class or C
+    structure. For some objects, like files, windows, mutexes, sockets, and others, a copy
+    constructor or an assignment operator are difficult to define. For some other objects, like
+    complex classifiers in OpenCV, copy constructors are absent and not easy to implement. Finally,
+    some of complex OpenCV and your own data structures may be written in C. However, copy
+    constructors and default constructors can simplify programming a lot. Besides, they are often
+    required (for example, by STL containers). By using a Ptr to such an object instead of the
+    object itself, you automatically get all of the necessary constructors and the assignment
+    operator.
+-   *O(1)* complexity of the above-mentioned operations. While some structures, like std::vector,
+    provide a copy constructor and an assignment operator, the operations may take a considerable
+    amount of time if the data structures are large. But if the structures are put into a Ptr, the
+    overhead is small and independent of the data size.
+-   Automatic and customizable cleanup, even for C structures. See the example below with FILE\*.
+-   Heterogeneous collections of objects. The standard STL and most other C++ and OpenCV containers
+    can store only objects of the same type and the same size. The classical solution to store
+    objects of different types in the same container is to store pointers to the base class (Base\*)
+    instead but then you lose the automatic memory management. Again, by using Ptr\<Base\> instead
+    of raw pointers, you can solve the problem.
+
+A Ptr is said to *own* a pointer - that is, for each Ptr there is a pointer that will be deleted
+once all Ptr instances that own it are destroyed. The owned pointer may be null, in which case
+nothing is deleted. Each Ptr also *stores* a pointer. The stored pointer is the pointer the Ptr
+pretends to be; that is, the one you get when you use Ptr::get or the conversion to T\*. It's
+usually the same as the owned pointer, but if you use casts or the general shared-ownership
+constructor, the two may diverge: the Ptr will still own the original pointer, but will itself point
+to something else.
+
+The owned pointer is treated as a black box. The only thing Ptr needs to know about it is how to
+delete it. This knowledge is encapsulated in the *deleter* - an auxiliary object that is associated
+with the owned pointer and shared between all Ptr instances that own it. The default deleter is an
+instance of DefaultDeleter, which uses the standard C++ delete operator; as such it will work with
+any pointer allocated with the standard new operator.
+
+However, if the pointer must be deleted in a different way, you must specify a custom deleter upon
+Ptr construction. A deleter is simply a callable object that accepts the pointer as its sole
+argument. For example, if you want to wrap FILE, you may do so as follows:
+@code
+    Ptr<FILE> f(fopen("myfile.txt", "w"), fclose);
+    if(!f) throw ...;
+    fprintf(f, ....);
+    ...
+    // the file will be closed automatically by f's destructor.
+@endcode
+Alternatively, if you want all pointers of a particular type to be deleted the same way, you can
+specialize DefaultDeleter<T>::operator() for that type, like this:
+@code
+    namespace cv {
+    template<> void DefaultDeleter<FILE>::operator ()(FILE * obj) const
+    {
+        fclose(obj);
+    }
+    }
+@endcode
+For convenience, the following types from the OpenCV C API already have such a specialization that
+calls the appropriate release function:
+-   CvCapture
+-   CvFileStorage
+-   CvHaarClassifierCascade
+-   CvMat
+-   CvMatND
+-   CvMemStorage
+-   CvSparseMat
+-   CvVideoWriter
+-   IplImage
+@note The shared ownership mechanism is implemented with reference counting. As such, cyclic
+ownership (e.g. when object a contains a Ptr to object b, which contains a Ptr to object a) will
+lead to all involved objects never being cleaned up. Avoid such situations.
+@note It is safe to concurrently read (but not write) a Ptr instance from multiple threads and
+therefore it is normally safe to use it in multi-threaded applications. The same is true for Mat and
+other C++ OpenCV classes that use internal reference counts.
+*/
+template<typename T>
+struct Ptr
+{
+    /** Generic programming support. */
+    typedef T element_type;
+
+    /** The default constructor creates a null Ptr - one that owns and stores a null pointer.
+    */
+    Ptr();
+
+    /**
+    If p is null, these are equivalent to the default constructor.
+    Otherwise, these constructors assume ownership of p - that is, the created Ptr owns and stores p
+    and assumes it is the sole owner of it. Don't use them if p is already owned by another Ptr, or
+    else p will get deleted twice.
+    With the first constructor, DefaultDeleter\<Y\>() becomes the associated deleter (so p will
+    eventually be deleted with the standard delete operator). Y must be a complete type at the point
+    of invocation.
+    With the second constructor, d becomes the associated deleter.
+    Y\* must be convertible to T\*.
+    @param p Pointer to own.
+    @note It is often easier to use makePtr instead.
+     */
+    template<typename Y>
+#ifdef DISABLE_OPENCV_24_COMPATIBILITY
+    explicit
+#endif
+    Ptr(Y* p);
+
+    /** @overload
+    @param d Deleter to use for the owned pointer.
+    @param p Pointer to own.
+    */
+    template<typename Y, typename D>
+    Ptr(Y* p, D d);
+
+    /**
+    These constructors create a Ptr that shares ownership with another Ptr - that is, own the same
+    pointer as o.
+    With the first two, the same pointer is stored, as well; for the second, Y\* must be convertible
+    to T\*.
+    With the third, p is stored, and Y may be any type. This constructor allows to have completely
+    unrelated owned and stored pointers, and should be used with care to avoid confusion. A relatively
+    benign use is to create a non-owning Ptr, like this:
+    @code
+        ptr = Ptr<T>(Ptr<T>(), dont_delete_me); // owns nothing; will not delete the pointer.
+    @endcode
+    @param o Ptr to share ownership with.
+    */
+    Ptr(const Ptr& o);
+
+    /** @overload
+    @param o Ptr to share ownership with.
+    */
+    template<typename Y>
+    Ptr(const Ptr<Y>& o);
+
+    /** @overload
+    @param o Ptr to share ownership with.
+    @param p Pointer to store.
+    */
+    template<typename Y>
+    Ptr(const Ptr<Y>& o, T* p);
+
+    /** The destructor is equivalent to calling Ptr::release. */
+    ~Ptr();
+
+    /**
+    Assignment replaces the current Ptr instance with one that owns and stores same pointers as o and
+    then destroys the old instance.
+    @param o Ptr to share ownership with.
+     */
+    Ptr& operator = (const Ptr& o);
+
+    /** @overload */
+    template<typename Y>
+    Ptr& operator = (const Ptr<Y>& o);
+
+    /** If no other Ptr instance owns the owned pointer, deletes it with the associated deleter. Then sets
+    both the owned and the stored pointers to NULL.
+    */
+    void release();
+
+    /**
+    `ptr.reset(...)` is equivalent to `ptr = Ptr<T>(...)`.
+    @param p Pointer to own.
+    */
+    template<typename Y>
+    void reset(Y* p);
+
+    /** @overload
+    @param d Deleter to use for the owned pointer.
+    @param p Pointer to own.
+    */
+    template<typename Y, typename D>
+    void reset(Y* p, D d);
+
+    /**
+    Swaps the owned and stored pointers (and deleters, if any) of this and o.
+    @param o Ptr to swap with.
+    */
+    void swap(Ptr& o);
+
+    /** Returns the stored pointer. */
+    T* get() const;
+
+    /** Ordinary pointer emulation. */
+    typename detail::RefOrVoid<T>::type operator * () const;
+
+    /** Ordinary pointer emulation. */
+    T* operator -> () const;
+
+    /** Equivalent to get(). */
+    operator T* () const;
+
+    /** ptr.empty() is equivalent to `!ptr.get()`. */
+    bool empty() const;
+
+    /** Returns a Ptr that owns the same pointer as this, and stores the same
+       pointer as this, except converted via static_cast to Y*.
+    */
+    template<typename Y>
+    Ptr<Y> staticCast() const;
+
+    /** Ditto for const_cast. */
+    template<typename Y>
+    Ptr<Y> constCast() const;
+
+    /** Ditto for dynamic_cast. */
+    template<typename Y>
+    Ptr<Y> dynamicCast() const;
+
+#ifdef CV_CXX_MOVE_SEMANTICS
+    Ptr(Ptr&& o);
+    Ptr& operator = (Ptr&& o);
+#endif
+
+private:
+    detail::PtrOwner* owner;
+    T* stored;
+
+    template<typename Y>
+    friend struct Ptr; // have to do this for the cross-type copy constructor
+};
+
+/** Equivalent to ptr1.swap(ptr2). Provided to help write generic algorithms. */
+template<typename T>
+void swap(Ptr<T>& ptr1, Ptr<T>& ptr2);
+
+/** Return whether ptr1.get() and ptr2.get() are equal and not equal, respectively. */
+template<typename T>
+bool operator == (const Ptr<T>& ptr1, const Ptr<T>& ptr2);
+template<typename T>
+bool operator != (const Ptr<T>& ptr1, const Ptr<T>& ptr2);
+
+/** `makePtr<T>(...)` is equivalent to `Ptr<T>(new T(...))`. It is shorter than the latter, and it's
+marginally safer than using a constructor or Ptr::reset, since it ensures that the owned pointer
+is new and thus not owned by any other Ptr instance.
+Unfortunately, perfect forwarding is impossible to implement in C++03, and so makePtr is limited
+to constructors of T that have up to 10 arguments, none of which are non-const references.
+ */
+template<typename T>
+Ptr<T> makePtr();
+/** @overload */
+template<typename T, typename A1>
+Ptr<T> makePtr(const A1& a1);
+/** @overload */
+template<typename T, typename A1, typename A2>
+Ptr<T> makePtr(const A1& a1, const A2& a2);
+/** @overload */
+template<typename T, typename A1, typename A2, typename A3>
+Ptr<T> makePtr(const A1& a1, const A2& a2, const A3& a3);
+/** @overload */
+template<typename T, typename A1, typename A2, typename A3, typename A4>
+Ptr<T> makePtr(const A1& a1, const A2& a2, const A3& a3, const A4& a4);
+/** @overload */
+template<typename T, typename A1, typename A2, typename A3, typename A4, typename A5>
+Ptr<T> makePtr(const A1& a1, const A2& a2, const A3& a3, const A4& a4, const A5& a5);
+/** @overload */
+template<typename T, typename A1, typename A2, typename A3, typename A4, typename A5, typename A6>
+Ptr<T> makePtr(const A1& a1, const A2& a2, const A3& a3, const A4& a4, const A5& a5, const A6& a6);
+/** @overload */
+template<typename T, typename A1, typename A2, typename A3, typename A4, typename A5, typename A6, typename A7>
+Ptr<T> makePtr(const A1& a1, const A2& a2, const A3& a3, const A4& a4, const A5& a5, const A6& a6, const A7& a7);
+/** @overload */
+template<typename T, typename A1, typename A2, typename A3, typename A4, typename A5, typename A6, typename A7, typename A8>
+Ptr<T> makePtr(const A1& a1, const A2& a2, const A3& a3, const A4& a4, const A5& a5, const A6& a6, const A7& a7, const A8& a8);
+/** @overload */
+template<typename T, typename A1, typename A2, typename A3, typename A4, typename A5, typename A6, typename A7, typename A8, typename A9>
+Ptr<T> makePtr(const A1& a1, const A2& a2, const A3& a3, const A4& a4, const A5& a5, const A6& a6, const A7& a7, const A8& a8, const A9& a9);
+/** @overload */
+template<typename T, typename A1, typename A2, typename A3, typename A4, typename A5, typename A6, typename A7, typename A8, typename A9, typename A10>
+Ptr<T> makePtr(const A1& a1, const A2& a2, const A3& a3, const A4& a4, const A5& a5, const A6& a6, const A7& a7, const A8& a8, const A9& a9, const A10& a10);
+
+//////////////////////////////// string class ////////////////////////////////
+
+class CV_EXPORTS FileNode; //for string constructor from FileNode
+
+class CV_EXPORTS String
+{
+public:
+    typedef char value_type;
+    typedef char& reference;
+    typedef const char& const_reference;
+    typedef char* pointer;
+    typedef const char* const_pointer;
+    typedef ptrdiff_t difference_type;
+    typedef size_t size_type;
+    typedef char* iterator;
+    typedef const char* const_iterator;
+
+    static const size_t npos = size_t(-1);
+
+    explicit String();
+    String(const String& str);
+    String(const String& str, size_t pos, size_t len = npos);
+    String(const char* s);
+    String(const char* s, size_t n);
+    String(size_t n, char c);
+    String(const char* first, const char* last);
+    template<typename Iterator> String(Iterator first, Iterator last);
+    explicit String(const FileNode& fn);
+    ~String();
+
+    String& operator=(const String& str);
+    String& operator=(const char* s);
+    String& operator=(char c);
+
+    String& operator+=(const String& str);
+    String& operator+=(const char* s);
+    String& operator+=(char c);
+
+    size_t size() const;
+    size_t length() const;
+
+    char operator[](size_t idx) const;
+    char operator[](int idx) const;
+
+    const char* begin() const;
+    const char* end() const;
+
+    const char* c_str() const;
+
+    bool empty() const;
+    void clear();
+
+    int compare(const char* s) const;
+    int compare(const String& str) const;
+
+    void swap(String& str);
+    String substr(size_t pos = 0, size_t len = npos) const;
+
+    size_t find(const char* s, size_t pos, size_t n) const;
+    size_t find(char c, size_t pos = 0) const;
+    size_t find(const String& str, size_t pos = 0) const;
+    size_t find(const char* s, size_t pos = 0) const;
+
+    size_t rfind(const char* s, size_t pos, size_t n) const;
+    size_t rfind(char c, size_t pos = npos) const;
+    size_t rfind(const String& str, size_t pos = npos) const;
+    size_t rfind(const char* s, size_t pos = npos) const;
+
+    size_t find_first_of(const char* s, size_t pos, size_t n) const;
+    size_t find_first_of(char c, size_t pos = 0) const;
+    size_t find_first_of(const String& str, size_t pos = 0) const;
+    size_t find_first_of(const char* s, size_t pos = 0) const;
+
+    size_t find_last_of(const char* s, size_t pos, size_t n) const;
+    size_t find_last_of(char c, size_t pos = npos) const;
+    size_t find_last_of(const String& str, size_t pos = npos) const;
+    size_t find_last_of(const char* s, size_t pos = npos) const;
+
+    friend String operator+ (const String& lhs, const String& rhs);
+    friend String operator+ (const String& lhs, const char*   rhs);
+    friend String operator+ (const char*   lhs, const String& rhs);
+    friend String operator+ (const String& lhs, char          rhs);
+    friend String operator+ (char          lhs, const String& rhs);
+
+    String toLowerCase() const;
+
+#ifndef OPENCV_NOSTL
+    String(const std::string& str);
+    String(const std::string& str, size_t pos, size_t len = npos);
+    String& operator=(const std::string& str);
+    String& operator+=(const std::string& str);
+    operator std::string() const;
+
+    friend String operator+ (const String& lhs, const std::string& rhs);
+    friend String operator+ (const std::string& lhs, const String& rhs);
+#endif
+
+private:
+    char*  cstr_;
+    size_t len_;
+
+    char* allocate(size_t len); // len without trailing 0
+    void deallocate();
+
+    String(int); // disabled and invalid. Catch invalid usages like, commandLineParser.has(0) problem
+};
+
+//! @} core_basic
+
+////////////////////////// cv::String implementation /////////////////////////
+
+//! @cond IGNORED
+
+inline
+String::String()
+    : cstr_(0), len_(0)
+{}
+
+inline
+String::String(const String& str)
+    : cstr_(str.cstr_), len_(str.len_)
+{
+    if (cstr_)
+        CV_XADD(((int*)cstr_)-1, 1);
+}
+
+inline
+String::String(const String& str, size_t pos, size_t len)
+    : cstr_(0), len_(0)
+{
+    pos = min(pos, str.len_);
+    len = min(str.len_ - pos, len);
+    if (!len) return;
+    if (len == str.len_)
+    {
+        CV_XADD(((int*)str.cstr_)-1, 1);
+        cstr_ = str.cstr_;
+        len_ = str.len_;
+        return;
+    }
+    memcpy(allocate(len), str.cstr_ + pos, len);
+}
+
+inline
+String::String(const char* s)
+    : cstr_(0), len_(0)
+{
+    if (!s) return;
+    size_t len = strlen(s);
+    memcpy(allocate(len), s, len);
+}
+
+inline
+String::String(const char* s, size_t n)
+    : cstr_(0), len_(0)
+{
+    if (!n) return;
+    memcpy(allocate(n), s, n);
+}
+
+inline
+String::String(size_t n, char c)
+    : cstr_(0), len_(0)
+{
+    memset(allocate(n), c, n);
+}
+
+inline
+String::String(const char* first, const char* last)
+    : cstr_(0), len_(0)
+{
+    size_t len = (size_t)(last - first);
+    memcpy(allocate(len), first, len);
+}
+
+template<typename Iterator> inline
+String::String(Iterator first, Iterator last)
+    : cstr_(0), len_(0)
+{
+    size_t len = (size_t)(last - first);
+    char* str = allocate(len);
+    while (first != last)
+    {
+        *str++ = *first;
+        ++first;
+    }
+}
+
+inline
+String::~String()
+{
+    deallocate();
+}
+
+inline
+String& String::operator=(const String& str)
+{
+    if (&str == this) return *this;
+
+    deallocate();
+    if (str.cstr_) CV_XADD(((int*)str.cstr_)-1, 1);
+    cstr_ = str.cstr_;
+    len_ = str.len_;
+    return *this;
+}
+
+inline
+String& String::operator=(const char* s)
+{
+    deallocate();
+    if (!s) return *this;
+    size_t len = strlen(s);
+    memcpy(allocate(len), s, len);
+    return *this;
+}
+
+inline
+String& String::operator=(char c)
+{
+    deallocate();
+    allocate(1)[0] = c;
+    return *this;
+}
+
+inline
+String& String::operator+=(const String& str)
+{
+    *this = *this + str;
+    return *this;
+}
+
+inline
+String& String::operator+=(const char* s)
+{
+    *this = *this + s;
+    return *this;
+}
+
+inline
+String& String::operator+=(char c)
+{
+    *this = *this + c;
+    return *this;
+}
+
+inline
+size_t String::size() const
+{
+    return len_;
+}
+
+inline
+size_t String::length() const
+{
+    return len_;
+}
+
+inline
+char String::operator[](size_t idx) const
+{
+    return cstr_[idx];
+}
+
+inline
+char String::operator[](int idx) const
+{
+    return cstr_[idx];
+}
+
+inline
+const char* String::begin() const
+{
+    return cstr_;
+}
+
+inline
+const char* String::end() const
+{
+    return len_ ? cstr_ + 1 : 0;
+}
+
+inline
+bool String::empty() const
+{
+    return len_ == 0;
+}
+
+inline
+const char* String::c_str() const
+{
+    return cstr_ ? cstr_ : "";
+}
+
+inline
+void String::swap(String& str)
+{
+    cv::swap(cstr_, str.cstr_);
+    cv::swap(len_, str.len_);
+}
+
+inline
+void String::clear()
+{
+    deallocate();
+}
+
+inline
+int String::compare(const char* s) const
+{
+    if (cstr_ == s) return 0;
+    return strcmp(c_str(), s);
+}
+
+inline
+int String::compare(const String& str) const
+{
+    if (cstr_ == str.cstr_) return 0;
+    return strcmp(c_str(), str.c_str());
+}
+
+inline
+String String::substr(size_t pos, size_t len) const
+{
+    return String(*this, pos, len);
+}
+
+inline
+size_t String::find(const char* s, size_t pos, size_t n) const
+{
+    if (n == 0 || pos + n > len_) return npos;
+    const char* lmax = cstr_ + len_ - n;
+    for (const char* i = cstr_ + pos; i <= lmax; ++i)
+    {
+        size_t j = 0;
+        while (j < n && s[j] == i[j]) ++j;
+        if (j == n) return (size_t)(i - cstr_);
+    }
+    return npos;
+}
+
+inline
+size_t String::find(char c, size_t pos) const
+{
+    return find(&c, pos, 1);
+}
+
+inline
+size_t String::find(const String& str, size_t pos) const
+{
+    return find(str.c_str(), pos, str.len_);
+}
+
+inline
+size_t String::find(const char* s, size_t pos) const
+{
+    if (pos >= len_ || !s[0]) return npos;
+    const char* lmax = cstr_ + len_;
+    for (const char* i = cstr_ + pos; i < lmax; ++i)
+    {
+        size_t j = 0;
+        while (s[j] && s[j] == i[j])
+        {   if(i + j >= lmax) return npos;
+            ++j;
+        }
+        if (!s[j]) return (size_t)(i - cstr_);
+    }
+    return npos;
+}
+
+inline
+size_t String::rfind(const char* s, size_t pos, size_t n) const
+{
+    if (n > len_) return npos;
+    if (pos > len_ - n) pos = len_ - n;
+    for (const char* i = cstr_ + pos; i >= cstr_; --i)
+    {
+        size_t j = 0;
+        while (j < n && s[j] == i[j]) ++j;
+        if (j == n) return (size_t)(i - cstr_);
+    }
+    return npos;
+}
+
+inline
+size_t String::rfind(char c, size_t pos) const
+{
+    return rfind(&c, pos, 1);
+}
+
+inline
+size_t String::rfind(const String& str, size_t pos) const
+{
+    return rfind(str.c_str(), pos, str.len_);
+}
+
+inline
+size_t String::rfind(const char* s, size_t pos) const
+{
+    return rfind(s, pos, strlen(s));
+}
+
+inline
+size_t String::find_first_of(const char* s, size_t pos, size_t n) const
+{
+    if (n == 0 || pos + n > len_) return npos;
+    const char* lmax = cstr_ + len_;
+    for (const char* i = cstr_ + pos; i < lmax; ++i)
+    {
+        for (size_t j = 0; j < n; ++j)
+            if (s[j] == *i)
+                return (size_t)(i - cstr_);
+    }
+    return npos;
+}
+
+inline
+size_t String::find_first_of(char c, size_t pos) const
+{
+    return find_first_of(&c, pos, 1);
+}
+
+inline
+size_t String::find_first_of(const String& str, size_t pos) const
+{
+    return find_first_of(str.c_str(), pos, str.len_);
+}
+
+inline
+size_t String::find_first_of(const char* s, size_t pos) const
+{
+    if (len_ == 0) return npos;
+    if (pos >= len_ || !s[0]) return npos;
+    const char* lmax = cstr_ + len_;
+    for (const char* i = cstr_ + pos; i < lmax; ++i)
+    {
+        for (size_t j = 0; s[j]; ++j)
+            if (s[j] == *i)
+                return (size_t)(i - cstr_);
+    }
+    return npos;
+}
+
+inline
+size_t String::find_last_of(const char* s, size_t pos, size_t n) const
+{
+    if (len_ == 0) return npos;
+    if (pos >= len_) pos = len_ - 1;
+    for (const char* i = cstr_ + pos; i >= cstr_; --i)
+    {
+        for (size_t j = 0; j < n; ++j)
+            if (s[j] == *i)
+                return (size_t)(i - cstr_);
+    }
+    return npos;
+}
+
+inline
+size_t String::find_last_of(char c, size_t pos) const
+{
+    return find_last_of(&c, pos, 1);
+}
+
+inline
+size_t String::find_last_of(const String& str, size_t pos) const
+{
+    return find_last_of(str.c_str(), pos, str.len_);
+}
+
+inline
+size_t String::find_last_of(const char* s, size_t pos) const
+{
+    if (len_ == 0) return npos;
+    if (pos >= len_) pos = len_ - 1;
+    for (const char* i = cstr_ + pos; i >= cstr_; --i)
+    {
+        for (size_t j = 0; s[j]; ++j)
+            if (s[j] == *i)
+                return (size_t)(i - cstr_);
+    }
+    return npos;
+}
+
+inline
+String String::toLowerCase() const
+{
+    String res(cstr_, len_);
+
+    for (size_t i = 0; i < len_; ++i)
+        res.cstr_[i] = (char) ::tolower(cstr_[i]);
+
+    return res;
+}
+
+//! @endcond
+
+// ************************* cv::String non-member functions *************************
+
+//! @relates cv::String
+//! @{
+
+inline
+String operator + (const String& lhs, const String& rhs)
+{
+    String s;
+    s.allocate(lhs.len_ + rhs.len_);
+    memcpy(s.cstr_, lhs.cstr_, lhs.len_);
+    memcpy(s.cstr_ + lhs.len_, rhs.cstr_, rhs.len_);
+    return s;
+}
+
+inline
+String operator + (const String& lhs, const char* rhs)
+{
+    String s;
+    size_t rhslen = strlen(rhs);
+    s.allocate(lhs.len_ + rhslen);
+    memcpy(s.cstr_, lhs.cstr_, lhs.len_);
+    memcpy(s.cstr_ + lhs.len_, rhs, rhslen);
+    return s;
+}
+
+inline
+String operator + (const char* lhs, const String& rhs)
+{
+    String s;
+    size_t lhslen = strlen(lhs);
+    s.allocate(lhslen + rhs.len_);
+    memcpy(s.cstr_, lhs, lhslen);
+    memcpy(s.cstr_ + lhslen, rhs.cstr_, rhs.len_);
+    return s;
+}
+
+inline
+String operator + (const String& lhs, char rhs)
+{
+    String s;
+    s.allocate(lhs.len_ + 1);
+    memcpy(s.cstr_, lhs.cstr_, lhs.len_);
+    s.cstr_[lhs.len_] = rhs;
+    return s;
+}
+
+inline
+String operator + (char lhs, const String& rhs)
+{
+    String s;
+    s.allocate(rhs.len_ + 1);
+    s.cstr_[0] = lhs;
+    memcpy(s.cstr_ + 1, rhs.cstr_, rhs.len_);
+    return s;
+}
+
+static inline bool operator== (const String& lhs, const String& rhs) { return 0 == lhs.compare(rhs); }
+static inline bool operator== (const char*   lhs, const String& rhs) { return 0 == rhs.compare(lhs); }
+static inline bool operator== (const String& lhs, const char*   rhs) { return 0 == lhs.compare(rhs); }
+static inline bool operator!= (const String& lhs, const String& rhs) { return 0 != lhs.compare(rhs); }
+static inline bool operator!= (const char*   lhs, const String& rhs) { return 0 != rhs.compare(lhs); }
+static inline bool operator!= (const String& lhs, const char*   rhs) { return 0 != lhs.compare(rhs); }
+static inline bool operator<  (const String& lhs, const String& rhs) { return lhs.compare(rhs) <  0; }
+static inline bool operator<  (const char*   lhs, const String& rhs) { return rhs.compare(lhs) >  0; }
+static inline bool operator<  (const String& lhs, const char*   rhs) { return lhs.compare(rhs) <  0; }
+static inline bool operator<= (const String& lhs, const String& rhs) { return lhs.compare(rhs) <= 0; }
+static inline bool operator<= (const char*   lhs, const String& rhs) { return rhs.compare(lhs) >= 0; }
+static inline bool operator<= (const String& lhs, const char*   rhs) { return lhs.compare(rhs) <= 0; }
+static inline bool operator>  (const String& lhs, const String& rhs) { return lhs.compare(rhs) >  0; }
+static inline bool operator>  (const char*   lhs, const String& rhs) { return rhs.compare(lhs) <  0; }
+static inline bool operator>  (const String& lhs, const char*   rhs) { return lhs.compare(rhs) >  0; }
+static inline bool operator>= (const String& lhs, const String& rhs) { return lhs.compare(rhs) >= 0; }
+static inline bool operator>= (const char*   lhs, const String& rhs) { return rhs.compare(lhs) <= 0; }
+static inline bool operator>= (const String& lhs, const char*   rhs) { return lhs.compare(rhs) >= 0; }
+
+//! @} relates cv::String
+
+} // cv
+
+#ifndef OPENCV_NOSTL_TRANSITIONAL
+namespace std
+{
+    static inline void swap(cv::String& a, cv::String& b) { a.swap(b); }
+}
+#else
+namespace cv
+{
+    template<> inline
+    void swap<cv::String>(cv::String& a, cv::String& b)
+    {
+        a.swap(b);
+    }
+}
+#endif
+
+#include "opencv2/core/ptr.inl.hpp"
+
+#endif //OPENCV_CORE_CVSTD_HPP