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<html><head><title>dlib C++ Library - any_abstract.h</title></head><body bgcolor='white'><pre> |
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<font color='#009900'>// Copyright (C) 2010 Davis E. King ([email protected]) |
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</font><font color='#009900'>// License: Boost Software License See LICENSE.txt for the full license. |
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</font><font color='#0000FF'>#undef</font> DLIB_AnY_ABSTRACT_H_ |
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<font color='#0000FF'>#ifdef</font> DLIB_AnY_ABSTRACT_H_ |
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<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>typeinfo<font color='#5555FF'>></font> |
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<font color='#0000FF'>namespace</font> dlib |
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<b>{</b> |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<font color='#0000FF'>class</font> <b><a name='bad_any_cast'></a>bad_any_cast</b> : <font color='#0000FF'>public</font> std::bad_cast |
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<b>{</b> |
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<font color='#009900'>/*! |
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WHAT THIS OBJECT REPRESENTS |
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This object is the exception class used by the any object. |
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It is used to indicate when someone attempts to cast an any |
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object into a type which isn't contained in the any object. |
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!*/</font> |
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<font color='#0000FF'>public</font>: |
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<font color='#0000FF'>virtual</font> <font color='#0000FF'>const</font> <font color='#0000FF'><u>char</u></font><font color='#5555FF'>*</font> <b><a name='what'></a>what</b><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> <font color='#0000FF'>throw</font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font> <b>{</b> <font color='#0000FF'>return</font> "<font color='#CC0000'>bad_any_cast</font>"; <b>}</b> |
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<b>}</b>; |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<font color='#0000FF'>class</font> <b><a name='any'></a>any</b> |
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<b>{</b> |
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<font color='#009900'>/*! |
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INITIAL VALUE |
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- is_empty() == true |
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- for all T: contains<T>() == false |
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WHAT THIS OBJECT REPRESENTS |
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This object is basically a type-safe version of a void*. In particular, |
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it is a container which can contain only one object but the object may |
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be of any type. |
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It is somewhat like the type_safe_union except you don't have to declare |
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the set of possible content types beforehand. So in some sense this is |
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like a less type-strict version of the type_safe_union. |
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!*/</font> |
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<font color='#0000FF'>public</font>: |
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<b><a name='any'></a>any</b><font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- this object is properly initialized |
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!*/</font> |
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<b><a name='any'></a>any</b> <font face='Lucida Console'>(</font> |
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<font color='#0000FF'>const</font> any<font color='#5555FF'>&</font> item |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- copies the state of item into *this. |
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- Note that *this and item will contain independent copies of the |
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contents of item. That is, this function performs a deep |
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copy and therefore does not result in *this containing |
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any kind of reference to item. |
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!*/</font> |
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<font color='#0000FF'>template</font> <font color='#5555FF'><</font> <font color='#0000FF'>typename</font> T <font color='#5555FF'>></font> |
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<b><a name='any'></a>any</b> <font face='Lucida Console'>(</font> |
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<font color='#0000FF'>const</font> T<font color='#5555FF'>&</font> item |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- #contains<T>() == true |
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- #cast_to<T>() == item |
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(i.e. a copy of item will be stored in *this) |
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!*/</font> |
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<font color='#0000FF'><u>void</u></font> <b><a name='clear'></a>clear</b> <font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- #*this will have its default value. I.e. #is_empty() == true |
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!*/</font> |
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<font color='#0000FF'>template</font> <font color='#5555FF'><</font><font color='#0000FF'>typename</font> T<font color='#5555FF'>></font> |
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<font color='#0000FF'><u>bool</u></font> <b><a name='contains'></a>contains</b> <font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>; |
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<font color='#009900'>/*! |
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ensures |
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- if (this object currently contains an object of type T) then |
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- returns true |
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- else |
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- returns false |
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!*/</font> |
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<font color='#0000FF'><u>bool</u></font> <b><a name='is_empty'></a>is_empty</b><font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>; |
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<font color='#009900'>/*! |
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ensures |
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- if (this object contains any kind of object) then |
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- returns false |
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- else |
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- returns true |
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!*/</font> |
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<font color='#0000FF'>template</font> <font color='#5555FF'><</font><font color='#0000FF'>typename</font> T<font color='#5555FF'>></font> |
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T<font color='#5555FF'>&</font> <b><a name='cast_to'></a>cast_to</b><font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- if (contains<T>() == true) then |
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- returns a non-const reference to the object contained within *this |
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- else |
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- throws bad_any_cast |
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!*/</font> |
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<font color='#0000FF'>template</font> <font color='#5555FF'><</font><font color='#0000FF'>typename</font> T<font color='#5555FF'>></font> |
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<font color='#0000FF'>const</font> T<font color='#5555FF'>&</font> <b><a name='cast_to'></a>cast_to</b><font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>; |
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<font color='#009900'>/*! |
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ensures |
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- if (contains<T>() == true) then |
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- returns a const reference to the object contained within *this |
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- else |
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- throws bad_any_cast |
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!*/</font> |
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<font color='#0000FF'>template</font> <font color='#5555FF'><</font><font color='#0000FF'>typename</font> T<font color='#5555FF'>></font> |
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T<font color='#5555FF'>&</font> <b><a name='get'></a>get</b><font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- #is_empty() == false |
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- #contains<T>() == true |
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- if (contains<T>() == true) |
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- returns a non-const reference to the object contained in *this. |
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- else |
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- Constructs an object of type T inside *this |
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- Any previous object stored in this any object is destructed and its |
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state is lost. |
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- returns a non-const reference to the newly created T object. |
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!*/</font> |
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any<font color='#5555FF'>&</font> <b><a name='operator'></a>operator</b><font color='#5555FF'>=</font> <font face='Lucida Console'>(</font> |
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<font color='#0000FF'>const</font> any<font color='#5555FF'>&</font> item |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- copies the state of item into *this. |
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- Note that *this and item will contain independent copies of the |
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contents of item. That is, this function performs a deep |
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copy and therefore does not result in *this containing |
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any kind of reference to item. |
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!*/</font> |
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<font color='#0000FF'><u>void</u></font> <b><a name='swap'></a>swap</b> <font face='Lucida Console'>(</font> |
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any<font color='#5555FF'>&</font> item |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- swaps *this and item |
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- does not invalidate pointers or references to the object contained |
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inside *this or item. Moreover, a pointer or reference to the object in |
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*this will now refer to the contents of #item and vice versa. |
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!*/</font> |
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<b>}</b>; |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<font color='#0000FF'>inline</font> <font color='#0000FF'><u>void</u></font> <b><a name='swap'></a>swap</b> <font face='Lucida Console'>(</font> |
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any<font color='#5555FF'>&</font> a, |
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any<font color='#5555FF'>&</font> b |
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<font face='Lucida Console'>)</font> <b>{</b> a.<font color='#BB00BB'>swap</font><font face='Lucida Console'>(</font>b<font face='Lucida Console'>)</font>; <b>}</b> |
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<font color='#009900'>/*! |
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provides a global swap function |
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!*/</font> |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<font color='#0000FF'>template</font> <font color='#5555FF'><</font> |
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<font color='#0000FF'>typename</font> T |
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<font color='#5555FF'>></font> |
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T<font color='#5555FF'>&</font> <b><a name='any_cast'></a>any_cast</b><font face='Lucida Console'>(</font> |
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any<font color='#5555FF'>&</font> a |
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<font face='Lucida Console'>)</font> <b>{</b> <font color='#0000FF'>return</font> a.cast_to<font color='#5555FF'><</font>T<font color='#5555FF'>></font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <b>}</b> |
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<font color='#009900'>/*! |
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ensures |
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- returns a.cast_to<T>() |
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!*/</font> |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<font color='#0000FF'>template</font> <font color='#5555FF'><</font> |
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<font color='#0000FF'>typename</font> T |
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<font color='#5555FF'>></font> |
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<font color='#0000FF'>const</font> T<font color='#5555FF'>&</font> <b><a name='any_cast'></a>any_cast</b><font face='Lucida Console'>(</font> |
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<font color='#0000FF'>const</font> any<font color='#5555FF'>&</font> a |
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<font face='Lucida Console'>)</font> <b>{</b> <font color='#0000FF'>return</font> a.cast_to<font color='#5555FF'><</font>T<font color='#5555FF'>></font><font face='Lucida Console'>(</font><font face='Lucida Console'>)</font>; <b>}</b> |
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<font color='#009900'>/*! |
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ensures |
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- returns a.cast_to<T>() |
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!*/</font> |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<b>}</b> |
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<font color='#0000FF'>#endif</font> <font color='#009900'>// DLIB_AnY_ABSTRACT_H_ |
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</font> |
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</pre></body></html> |
