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Some additional functions added to optional (being new there won't be regressions)
[SVN r34411]
This commit is contained in:
Fernando Cacciola
@ -3,7 +3,6 @@
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@ -324,6 +323,8 @@ class optional
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optional ( T const& v ) ;
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optional ( bool condition, T const& v ) ; <u><i>[new in 1.34]</u></i>
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optional ( optional const& rhs ) ;
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template<class U> explicit optional ( optional<U> const& rhs ) ;
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@ -347,6 +348,8 @@ class optional
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T const& get() const ;
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T& get() ;
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T<span lang="es"> const&</span> get_value_or( T const& default ) const ; <u><i>[new in 1.34]</u></i>
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T const* operator ->() const ;
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T* operator ->() ;
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@ -380,6 +383,12 @@ template<class T> inline bool operator <= ( optional<T> const& x, op
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template<class T> inline bool operator >= ( optional<T> const& x, optional<T> const& y ) ;
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template<class T> inline optional<T> make_optional ( T const& v ) ; <u><i>[new in 1.34]</u></i>
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template<class T> inline optional<T> make_optional ( bool condition, T const& v ) ; <u><i>[new in 1.34]</u></i>
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template<class T> inline T <span lang="es">const& </span>get_<span lang="es">optional_</span>value_or ( optional<T> const& opt, T const& default ) ; <u><i>[new in 1.34]</u></i>
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template<class T> inline T const& get ( optional<T> const& opt ) ;
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template<class T> inline T& get ( optional<T> & opt ) ;
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@ -436,7 +445,7 @@ assert ( !def ) ;</pre>
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<pre>optional<T>::optional( none_t );</pre>
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<blockquote>
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<p><b>Effect:</b> Constructs an <b>optional </b>uninitialized.</p>
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<p><b>Effect:</b> Constructs an <b>optional</b> uninitialized.</p>
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<p><b>Postconditions:</b> <b>*this</b> is <u>uninitialized</u>.</p>
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<p><b>Throws:</b> Nothing.</p>
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<p><b>Notes:</b></p>
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@ -459,7 +468,6 @@ assert ( !n ) ;</pre>
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<pre>optional<T <i>(not a ref)</i>>::optional( T const& v )</pre>
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<blockquote>
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<p><b>Effect:</b> Directly-Constructs an <b>optional</b>.</p>
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<!-- TemplateName: general/sy_footer_inc.isml -->
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<p><b>Postconditions:</b> <b>*this</b> is <u>initialized</u> and its value is a <i>copy</i> of 'v'.</p>
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<p><b>Throws:</b> Whatever T::T( T const& ) throws.</p>
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<p><b>Notes: </b> T::T( T const& ) is called.</p>
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@ -495,6 +503,23 @@ assert (*opt == v); </pre>
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<HR>
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<pre>optional<T <i>(not a ref)</i>>::optional( bool condition, T const& v ) ;
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optional<T&> <span lang="es"> </span>::optional( bool condition, T& <span lang="es"> </span> v ) ;
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</pre>
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<blockquote>
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<p>If <i>condition</i> is <code>true</code>, same as:</p>
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<pre>optional<T <i>(not a ref)</i>>::optional( T const& v )
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optional<T&><span lang="es"> </span>::optional( T&<span lang="es"> </span> v )
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</pre>
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<p>otherwise, same as:</p>
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<pre>optional<T <i>(not a ref)</i>>::optional()
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optional<T&><span lang="es"> </span>::optional()
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</pre>
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</blockquote>
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<HR>
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<pre>optional<T <i>(not a ref)</i>>::optional( optional const& rhs );</pre>
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<blockquote>
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<p><b>Effect:</b> Copy-Constructs an <b>optional</b>.</p>
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@ -797,7 +822,6 @@ assert ( *opt1 == static_cast<U>(v) ) ;
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<HR>
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<pre>T const& optional<T <i>(not a ref)</i>>::operator*() const ;
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T& optional<T<i> (not a ref)</i>>::operator*();</pre>
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@ -828,6 +852,32 @@ assert ( *opt == w ) ;
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<HR>
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<pre>T const& optional<T <i>(not a ref)</i>>::get_value_or( T const& default) const ;
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T& optional<T <i>(not a ref)</i>>::get_value_or( T& default ) ;
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inline T const& get_optional_value_or ( optional<T<i> (not a ref)</i>> const& o, T const& default ) ;
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inline T& get_optional_value_or ( optional<T <i>(not a ref)</i>>& o, T& default ) ;
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</pre>
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<blockquote>
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<p><b>Returns:</b> A reference to the contained value, if any, or <code>default</code></p>
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<p><b>Throws:</b> Nothing.</p>
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<p><b>Example:</b></p>
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<blockquote>
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<pre>T v, z ;
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optional<T> def;
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T const& y = def.get_value_or(z);
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assert ( y == z ) ;
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optional<T> opt ( v );
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T const& u = get_optional_value_or(opt,z);
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assert ( u == v ) ;
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assert ( u != z ) ;
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</pre>
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</blockquote>
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<pre></pre>
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</blockquote>
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<HR>
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<pre>T const& optional<T&>::operator*() const ;
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T & optional<T<i>&</i>>::operator*();</pre>
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@ -965,18 +1015,47 @@ assert ( opt.is_initialized() );</pre>
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<HR>
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<pre>optional<T <i>(not a ref)</i>> make_optional( T const& v )</pre>
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<blockquote>
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<p><b>Returns:</b> optional<T>(v) for the <i>deduced</i> type <code>T</code> of <code>v</code>.</p>
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<p><b>Example:</b></p>
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<blockquote>
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<pre>template<class T> void foo ( optional<T> const& opt ) ;
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foo ( make_optional(1+1) ) ; // Creates an optional<int>
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</blockquote>
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</blockquote>
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<HR>
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<pre>optional<T <i>(not a ref)</i>> make_optional( bool condition, T const& v )</pre>
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<blockquote>
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<p><b>Returns:</b> optional<T>(condition,v) for the <i>deduced</i> type <code>T</code> of <code>v</code>.</p>
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<p><b>Example:</b></p>
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<blockquote>
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<pre>optional<double> calculate_foo()
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{
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double val = compute_foo();
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return make_optional(is_not_nan_and_finite(val),val);
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}
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optional<double> v = calculate_foo();
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if ( !v )
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error("foo wasn't computed");
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</blockquote>
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</blockquote>
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<HR>
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<pre>bool operator == ( optional<T> const& x, optional<T> const& y );</pre>
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<blockquote>
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<p><b>Returns:</b> If both <b>x</b> and <b>y</b> are initialied, <code>(*x == *y)</code>.
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If only x or y is initialized, <code>false</code>. If both are uninitialized, <code>true</code>.
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</p>
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If only x or y is initialized, <code>false</code>. If both are uninitialized, <code>true</code>. </p>
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<p><b>Throws:</b> Nothing.</p>
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<p><b>Notes:</b> Pointers have shallow relational operators while <b>optional</b> has
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deep relational operators. Do not use operator == directly in generic code
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which expect to be given either an optional<T> or a pointer;
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use <a href="../../utility/OptionalPointee.html#equal">equal_pointees()</a> instead
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</p>
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use <a href="../../utility/OptionalPointee.html#equal">equal_pointees()</a> instead </p>
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<p><b>Example:</b></p>
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<blockquote>
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<pre>T x(12);
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@ -1012,14 +1091,12 @@ assert ( optX != optZ ) ;
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<blockquote>
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<p><b>Returns:</b> If <b>y</b> is not initialized, <code>false</code>.
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If <b>y</b> is initialized and <b>x</b> is not initialized, <code>true</code>.
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If both <b>x</b> and <b>y</b> are initialized, <code>(*x < *y)</code>.
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</p>
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If both <b>x</b> and <b>y</b> are initialized, <code>(*x < *y)</code>. </p>
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<p><b>Throws:</b> Nothing.</p>
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<p><b>Notes:</b> Pointers have shallow relational operators while <b>optional</b> has
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deep relational operators. Do not use operator < directly in generic code
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which expect to be given either an optional<T> or a pointer;
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use <a href="../../utility/OptionalPointee.html#less">less_pointees()</a> instead
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</p>
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use <a href="../../utility/OptionalPointee.html#less">less_pointees()</a> instead </p>
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<p><b>Example:</b></p>
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<blockquote>
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<pre>T x(12);
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@ -1082,23 +1159,17 @@ assert ( optX != optZ ) ;
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<pre>void swap ( optional<T>& x, optional<T>& y );</pre>
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<blockquote>
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<p><b>Effect:</b> If both <b>x</b> and <b>y</b> are initialized, calls <code>swap(*x,*y)</code>
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using std::swap.<br>
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<p><b>Effect:</b> If both <b>x</b> and <b>y</b> are initialized, calls <code>swap(*x,*y)</code> using std::swap.<br>
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If only one is initialized, say x, calls: <code>y.reset(*x); x.reset();</code><br>
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If none is initialized, does nothing.
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</p>
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If none is initialized, does nothing. </p>
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<p><b>Postconditions:</b> The states of x and y interchanged.</p>
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<p><b>Throws:</b> If both are initialized, whatever swap(T&,T&) throws.
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If only one is initialized, whatever T::T ( T const& ) throws.
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</p>
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<p><b>Notes:</b> If both are initialized, swap(T&,T&) is used <i>unqualified</i>
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but with std::swap introduced in scope.<br>
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If only one is initialized, T::~T() and T::T( T const& ) is called.
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</p>
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If only one is initialized, whatever T::T ( T const& ) throws. </p>
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<p><b>Notes:</b> If both are initialized, swap(T&,T&) is used <i>unqualified</i> but with std::swap introduced in scope.<br>
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If only one is initialized, T::~T() and T::T( T const& ) is called. </p>
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<p><b>Exception Safety:</b> If both are initialized, this operation has the exception
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safety guarantees of swap(T&,T&).<br>
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If only one is initialized, it has the same <b>basic</b> guarantee as optional<T>::reset( T const& ).
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</p>
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If only one is initialized, it has the same <b>basic</b> guarantee as optional<T>::reset( T const& ). </p>
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<p><b>Example:</b></p>
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<blockquote>
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<pre>T x(12);
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@ -1254,8 +1325,7 @@ assert(a==b);
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b = 3 ;
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assert(ra!=b); // 'ra' is not rebound to 'b'
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</pre>
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<p>Now, if you assign to an <i>initialized</i> optional<T&>, the effect is to <b>
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rebind</b> to the new object instead of assigning the referee. This is unlike
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<p>Now, if you assign to an <i>initialized</i> optional<T&>, the effect is to <b>rebind</b> to the new object instead of assigning the referee. This is unlike
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bare C++ references.</p>
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<pre>int a = 1 ;
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int b = 2 ;
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@ -1358,8 +1428,7 @@ public:
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</pre>
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<p>A limitation of this method is that it doesn't scale well to wrapped objects with multiple
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constructors nor to generic code were the constructor overloads are unknown.</p>
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<p>The solution presented in this library is the family of <b>InPlaceFactories</b> and
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<b>TypedInPlaceFactories</b>.<br>
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<p>The solution presented in this library is the family of <b>InPlaceFactories</b> and <b>TypedInPlaceFactories</b>.<br>
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These factories are a family of classes which encapsulate an increasing number of arbitrary
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constructor parameters and supply a method to construct an object of a given type using those
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parameters at an address specified by the user via placement new.</p>
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@ -1427,10 +1496,7 @@ public:
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W ( in_place(123,"hello") ) ;
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}
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</pre>
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<p>The factories are implemented in the headers:
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<a href="../../../boost/utility/in_place_factory.hpp">in_place_factory.hpp</a> and
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<a href="../../../boost/utility/typed_in_place_factory.hpp">typed_in_place_factory.hpp</a>
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</p>
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<p>The factories are implemented in the headers: <a href="../../../boost/utility/in_place_factory.hpp">in_place_factory.hpp</a> and <a href="../../../boost/utility/typed_in_place_factory.hpp">typed_in_place_factory.hpp</a> </p>
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<HR>
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@ -1473,8 +1539,7 @@ of the assignment methods:</p>
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TypedInPlaceFactory const& ) </code></li>
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<li> <code>optional<T>:::reset ( T const&)</code></li>
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</ul>
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<p>Can only <i>guarantee</i> the <u>basic exception safety</u>: The lvalue optional is left <u>uninitialized</u>
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if an exception is thrown (any previous value is <i>first</i> destroyed using T::~T())</p>
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<p>Can only <i>guarantee</i> the <u>basic exception safety</u>: The lvalue optional is left <u>uninitialized</u> if an exception is thrown (any previous value is <i>first</i> destroyed using T::~T())</p>
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<p>On the other hand, the <i>uninitializing</i> methods:</p>
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<ul>
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<li><code>optional<T>::operator= ( detail::none_t ) </code></li>
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@ -1603,12 +1668,9 @@ T <u>is not</u> required to be <a href="http://www.sgi.com/tech/stl/DefaultConst
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<P>Revised April 21, 2005</P>
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<p><EFBFBD> Copyright Fernando Luis Cacciola Carballal, 2003,2004,2005</p>
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<p> Use, modification, and distribution are subject to the Boost Software
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License, Version 1.0. (See accompanying file <a href="../../../LICENSE_1_0.txt">
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LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
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www.boost.org/LICENSE_1_0.txt</a>)</p>
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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">www.boost.org/LICENSE_1_0.txt</a>)</p>
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<P>Developed by <A HREF="mailto:fernando_cacciola@hotmail.com">Fernando Cacciola</A>,
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the latest version of this file can be found at <A
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HREF="http://www.boost.org">www.boost.org</A>, and the boost
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<A HREF="http://www.boost.org/more/mailing_lists.htm#main">discussion lists</A></P>
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</BODY>
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HREF="http://www.boost.org">www.boost.org</A>, and the boost <A HREF="http://www.boost.org/more/mailing_lists.htm#main">discussion lists</A></P>
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