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| <h1><img height="86" alt="boost.png (6897 bytes)" src="../../boost.png" |
| width="277" align="middle" border="0">make_unique</h1> |
| <p><a href="#introduction">Introduction</a><br> |
| <a href="#synopsis">Synopsis</a><br> |
| <a href="#common">Common Requirements</a><br> |
| <a href="#functions">Free Functions</a><br> |
| <a href="#history">History</a></p> |
| <h2><a name="introduction">Introduction</a></h2> |
| <p>The header file <boost/make_unique.hpp> provides overloaded |
| function template <code>make_unique</code> for convenient creation of |
| <code>unique_ptr</code> objects.</p> |
| <h2><a name="synopsis">Synopsis</a></h2> |
| <pre>namespace boost { |
| template<class U> // U is not array |
| unique_ptr<U> <a href="#functions">make_unique</a>(); |
| |
| #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) |
| template<class U, class... Args> // U is not array |
| unique_ptr<U> <a href="#functions">make_unique</a>(Args&&... args); |
| #endif |
| |
| template<class U> // U is not array |
| unique_ptr<U> <a href="#functions">make_unique</a>(U&& value); |
| |
| template<class U> // U is T[] |
| unique_ptr<U> <a href="#functions">make_unique</a>(size_t size); |
| |
| template<class U> // U is not array |
| unique_ptr<U> <a href="#functions">make_unique_noinit</a>(); |
| |
| template<class U> // U is T[] |
| unique_ptr<U> <a href="#functions">make_unique_noinit</a>(size_t size); |
| }</pre> |
| <h2><a name="common">Common Requirements</a></h2> |
| <pre>template<class U> |
| unique_ptr<U> make_unique(<em>args</em>); |
| template<class U> |
| unique_ptr<U> make_unique_noinit(<em>args</em>);</pre> |
| <blockquote> |
| <p><b>Effects:</b> Allocates memory for an object of type <code>U</code> |
| (or <code>T[size]</code> when <code>U</code> is <code>T[]</code>, |
| where <code>size</code> is determined from <code>args</code> as |
| specified by the concrete overload). The object is initialized from |
| <code>args</code> as specified by the concrete overload. If an |
| exception is thrown, the functions have no effect.</p> |
| <p><b>Returns:</b> A <code>unique_ptr</code> instance that stores and |
| owns the address of the newly constructed object.</p> |
| <p><b>Postconditions:</b> <code>r.get() != 0</code>, where |
| <code>r</code> is the return value.</p> |
| <p><b>Throws:</b> <code>bad_alloc</code>, or an exception thrown from |
| the initialization of the object.</p> |
| <p><b>Remarks:</b></p> |
| <blockquote> |
| <p>When an object of a non-array type <code>T</code> is specified to |
| be initialized to a value <code>value</code>, or to |
| <code>T(list...)</code>, where <code>list...</code> is a list of |
| constructor arguments, <code>make_unique</code> shall perform this |
| initialization via the expression <code>new T(value)</code> or |
| <code>new T(list...)</code> respectively.</p> |
| <p>When an object of type <code>T</code> is specified to be |
| value-initialized, <code>make_unique</code> shall perform this |
| initialization via the expression <code>new T()</code>.</p> |
| <p>When an object of type <code>T</code> is specified to be |
| default-initialized, <code>make_unique_noinit</code> shall perform |
| this initialization via the expression <code>new T</code>.</p> |
| </blockquote> |
| </blockquote> |
| <h2><a name="functions">Free Functions</a></h2> |
| <pre>template<class U, class... Args> |
| unique_ptr<U> make_unique(Args&&... args);</pre> |
| <blockquote> |
| <p><b>Returns:</b> A unique_ptr to an object of type <code>U</code>, |
| initialized to <code>U(forward<Args>(args)...)</code>.</p> |
| <p><b>Remarks:</b> This overload shall only participate in overload |
| resolution when <code>U</code> is not an array type.</p> |
| <p><b>Examples:</b></p> |
| <blockquote> |
| <pre>unique_ptr<float> p1 = boost::make_unique<float>(); |
| unique_ptr<point> p2 = boost::make_unique<point>(x, y);</pre> |
| </blockquote> |
| </blockquote> |
| <pre>template<class U> |
| unique_ptr<U> make_unique(U&& value);</pre> |
| <blockquote> |
| <p><b>Returns:</b> A unique_ptr to an object of type <code>U</code>, |
| initialized to <code>move(value)</code>.</p> |
| <p><b>Remarks:</b> This overload shall only participate in overload |
| resolution when <code>U</code> is not an array type.</p> |
| <p><b>Examples:</b></p> |
| <blockquote> |
| <pre>unique_ptr<string> p1 = boost::make_unique<string>({'a', 'b'}); |
| unique_ptr<point> p2 = boost::make_unique<point>({-10, 25});</pre> |
| </blockquote> |
| </blockquote> |
| <pre>template<class U> |
| unique_ptr<U> make_unique(size_t size);</pre> |
| <blockquote> |
| <p><b>Returns:</b> A unique_ptr to a value-initialized object of type |
| <code>T[size]</code>.</p> |
| <p><b>Remarks:</b> This overload shall only participate in overload |
| resolution when <code>U</code> is of the form <code>T[]</code>.</p> |
| <p><b>Examples:</b></p> |
| <blockquote> |
| <pre>unique_ptr<double[]> p1 = boost::make_unique<double[]>(4); |
| unique_ptr<int[][2]> p2 = boost::make_unique<int[][2]>(2);</pre> |
| </blockquote> |
| </blockquote> |
| <pre>template<class U> |
| unique_ptr<U> make_unique_noinit();</pre> |
| <blockquote> |
| <p><b>Returns:</b> A unique_ptr to a default-initialized object of |
| type <code>U</code>.</p> |
| <p><b>Remarks:</b> This overload shall only participate in overload |
| resolution when <code>U</code> is not an array type.</p> |
| <p><b>Examples:</b></p> |
| <blockquote> |
| <pre>unique_ptr<float> p1 = boost::make_unique_noinit<float>(); |
| unique_ptr<point> p2 = boost::make_unique_noinit<point>();</pre> |
| </blockquote> |
| </blockquote> |
| <pre>template<class U> |
| unique_ptr<U> make_unique_noinit(size_t size);</pre> |
| <blockquote> |
| <p><b>Returns:</b> A unique_ptr to a default-initialized object of |
| type <code>T[size]</code>.</p> |
| <p><b>Remarks:</b> This overload shall only participate in overload |
| resolution when <code>U</code> is of the form <code>T[]</code>.</p> |
| <p><b>Examples:</b></p> |
| <blockquote> |
| <pre>unique_ptr<double[]> p1 = boost::make_unique_noinit<double[]>(4); |
| unique_ptr<int[][2]> p2 = boost::make_unique_noinit<int[][2]>(2);</pre> |
| </blockquote> |
| </blockquote> |
| <h2><a name="history">History</a></h2> |
| <p>January 2014. Glen Fernandes contributed implementations of |
| make_unique for objects and arrays.</p> |
| <hr> |
| <p>$Date$</p> |
| <p><small>Copyright 2012-2014 Glen Fernandes. Distributed under the |
| Boost Software License, Version 1.0. See accompanying file |
| <a href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or copy at |
| <a href="http://www.boost.org/LICENSE_1_0.txt"> |
| http://www.boost.org/LICENSE_1_0.txt</a>.</small></p> |
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