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fixed a bug in example code

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[SVN r15576]
This commit is contained in:
Jaakko Järvi
2002-09-30 20:40:07 +00:00
parent 4227c144de
commit 0323ca1876
9 changed files with 53 additions and 50 deletions
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doc/lambda_docs_as_one_file.html
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@@ -259,7 +259,7 @@ for_each(v.begin(), v.end(), _1 = 1);</pre>
Next, we create a container of pointers and make them point to the elements in the first container <tt>v</tt>:
<pre class="programlisting">
list&lt;int*&gt; vp(10);
vector&lt;int*&gt; vp(10);
transform(v.begin(), v.end(), vp.begin(), &amp;_1);</pre>
The expression <tt>&amp;_1</tt> creates a function object for getting the address of each element in <tt>v</tt>.
@@ -997,7 +997,7 @@ Here is an example of naming a delayed constant:
constant_type&lt;char&gt;::type space(constant(' '));
for_each(a.begin(),a.end(), cout &lt;&lt; space &lt;&lt; _1);
</pre>
</p></div><div class="simplesect"><div class="titlepage"><div><h4 class="title"><a name="id2793531"></a>About assignment and subscript operators</h4></div></div><p>
</p></div><div class="simplesect"><div class="titlepage"><div><h4 class="title"><a name="id2793532"></a>About assignment and subscript operators</h4></div></div><p>
As described in <a href="#sect:assignment_and_subscript" title="5.2.2. Assignment and subscript operators">Section 5.2.2</a>, assignment and subscripting operators are always defined as member functions.
This means, that for expressions of the form
<tt>x = y</tt> or <tt>x[y]</tt> to be interpreted as lambda expressions, the left-hand operand <tt>x</tt> must be a lambda expression.
@@ -1070,13 +1070,7 @@ for_each(a, a+5,
The BLL supports an alternative syntax for control expressions, suggested
by Joel de Guzmann.
By overloading the <tt>operator[]</tt> we can
get a closer resemblance with the built-in control structures.
For example, using this syntax the <tt>if_then</tt> example above
can be written as:
<pre class="programlisting">
for_each(a.begin(), a.end(),
if(_1 % 2 == 0)[ cout &lt;&lt; _1 ])
</pre>
get a closer resemblance with the built-in control structures:
<pre class="programlisting">
if_(condition)[then_part]
@@ -1086,6 +1080,13 @@ do_[body].while_(condition)
for_(init, condition, increment)[body]
</pre>
For example, using this syntax the <tt>if_then</tt> example above
can be written as:
<pre class="programlisting">
for_each(a.begin(), a.end(),
if(_1 % 2 == 0)[ cout &lt;&lt; _1 ])
</pre>
As more experience is gained, we may end up deprecating one or the other
of these syntaces.
@@ -1284,7 +1285,7 @@ objects related to creating and destroying objects,
showing the expression to create and call the function object,
and the effect of evaluating that expression.
</p><div class="table"><p><a name="table:constructor_destructor_fos"></a><b>Table 1. Construction and destruction related function objects.</b></p><table summary="Construction and destruction related function objects." border="1"><colgroup><col><col></colgroup><thead><tr><th>Function object call</th><th>Wrapped expression</th></tr></thead><tbody><tr><td><tt>constructor&lt;T&gt;()(<i><tt>arg_list</tt></i>)</tt></td><td>T(<i><tt>arg_list</tt></i>)</td></tr><tr><td><tt>destructor()(a)</tt></td><td><tt>a.~A()</tt>, where <tt>a</tt> is of type <tt>A</tt></td></tr><tr><td><tt>destructor()(pa)</tt></td><td><tt>pa.-&gt;A()</tt>, where <tt>pa</tt> is of type <tt>A*</tt></td></tr><tr><td><tt>new_ptr&lt;T&gt;()(<i><tt>arg_list</tt></i>)</tt></td><td><tt>new T(<i><tt>arg_list</tt></i>)</tt></td></tr><tr><td><tt>new_array&lt;T&gt;()(sz)</tt></td><td><tt>new T[sz]</tt></td></tr><tr><td><tt>delete_ptr()(p)</tt></td><td><tt>delete p</tt></td></tr><tr><td><tt>delete_array()(p)</tt></td><td><tt>delete p[]</tt></td></tr></tbody></table></div></div><div class="section"><div class="titlepage"><div><h3 class="title"><a name="id2794800"></a>5.9. Special lambda expressions</h3></div></div><div class="section"><div class="titlepage"><div><h4 class="title"><a name="id2794808"></a>5.9.1. Preventing argument substitution</h4></div></div><p>
</p><div class="table"><p><a name="table:constructor_destructor_fos"></a><b>Table 1. Construction and destruction related function objects.</b></p><table summary="Construction and destruction related function objects." border="1"><colgroup><col><col></colgroup><thead><tr><th>Function object call</th><th>Wrapped expression</th></tr></thead><tbody><tr><td><tt>constructor&lt;T&gt;()(<i><tt>arg_list</tt></i>)</tt></td><td>T(<i><tt>arg_list</tt></i>)</td></tr><tr><td><tt>destructor()(a)</tt></td><td><tt>a.~A()</tt>, where <tt>a</tt> is of type <tt>A</tt></td></tr><tr><td><tt>destructor()(pa)</tt></td><td><tt>pa.-&gt;A()</tt>, where <tt>pa</tt> is of type <tt>A*</tt></td></tr><tr><td><tt>new_ptr&lt;T&gt;()(<i><tt>arg_list</tt></i>)</tt></td><td><tt>new T(<i><tt>arg_list</tt></i>)</tt></td></tr><tr><td><tt>new_array&lt;T&gt;()(sz)</tt></td><td><tt>new T[sz]</tt></td></tr><tr><td><tt>delete_ptr()(p)</tt></td><td><tt>delete p</tt></td></tr><tr><td><tt>delete_array()(p)</tt></td><td><tt>delete p[]</tt></td></tr></tbody></table></div></div><div class="section"><div class="titlepage"><div><h3 class="title"><a name="id2794800"></a>5.9. Special lambda expressions</h3></div></div><div class="section"><div class="titlepage"><div><h4 class="title"><a name="id2794807"></a>5.9.1. Preventing argument substitution</h4></div></div><p>
When a lambda functor is called, the default behavior is to substitute
the actual arguments for the placeholders within all subexpressions.
@@ -1932,7 +1933,7 @@ The BLL works with the following compilers, that is, the compilers are capable o
)
</li></ul></div>
</p><div class="section"><div class="titlepage"><div><h4 class="title"><a name="id2797482"></a>7.3.1. Test coverage</h4></div></div><p>The following list describes the test files included and the features that each file covers:
</p><div class="section"><div class="titlepage"><div><h4 class="title"><a name="id2797481"></a>7.3.1. Test coverage</h4></div></div><p>The following list describes the test files included and the features that each file covers:
<div class="itemizedlist"><ul type="disc"><li><p>
<tt>bind_tests_simple.cpp</tt> : Bind expressions of different arities and types of target functions: function pointers, function objects and member functions.
@@ -1986,14 +1987,14 @@ lambda functors; and these wrappers have types that are easy to type out.
For example:
<pre class="programlisting">
boost::function&lt;int, int, int&gt; f = _1 + _2;
boost::function&lt;int&amp;, int&amp;&gt; g = unlambda(_1 += 10);
boost::function&lt;int(int, int)&gt; f = _1 + _2;
boost::function&lt;int&amp;(int&amp;)&gt; g = (_1 += 10);
int i = 1, j = 2;
f(i); // returns 3
g(i); // sets i to = 11;
</pre>
The return and parameter types of the wrapped function object must be written explicilty as template arguments to the wrapper template <tt>boost::function</tt>; even when lambda functors, which otherwise have generic parameters, are wrapped.
The return and parameter types of the wrapped function object must be written explicilty as the template argument to the wrapper template <tt>boost::function</tt>; even when lambda functors, which otherwise have generic parameters, are wrapped.
Wrapping a function object with <tt>boost::function</tt> introduces a performance cost comparable to virtual function dispatch, though virtual functions are not actually used.
Note that storing lambda functors inside <tt>boost::function</tt>
@@ -2011,7 +2012,7 @@ For example:
<pre class="programlisting">
int* sum = new int();
*sum = 0;
boost::function&lt;int&amp;, int&gt; counter = *sum += _1;
boost::function&lt;int&amp;(int)&gt; counter = *sum += _1;
counter(5); // ok, *sum = 5;
delete sum;
counter(3); // error, *sum does not exist anymore
@@ -2036,7 +2037,7 @@ a larger set of compilers.
</p><p>
The following two sections describe what are the semantic differences
between the bind expressions in BB and BLL.
</p><div class="section"><div class="titlepage"><div><h4 class="title"><a name="id2798003"></a>8.2.1. First argument of bind expression</h4></div></div>
</p><div class="section"><div class="titlepage"><div><h4 class="title"><a name="id2798002"></a>8.2.1. First argument of bind expression</h4></div></div>
In BB the first argument of the bind expression, the target function,
is treated differently from the other arguments,