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58<span id="Assignment-Type-Conversions"></span><div class="header">
59<p>
60Next: <a href="Argument-Promotions.html" accesskey="n" rel="next">Argument Promotions</a>, Previous: <a href="Explicit-Type-Conversion.html" accesskey="p" rel="prev">Explicit Type Conversion</a>, Up: <a href="Type-Conversions.html" accesskey="u" rel="up">Type Conversions</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Index.html" title="Index" rel="index">Index</a>]</p>
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62<hr>
63<span id="Assignment-Type-Conversions-1"></span><h3 class="section">24.2 Assignment Type Conversions</h3>
64<span id="index-assignment-type-conversions"></span>
65
66<p>Certain type conversions occur automatically in assignments
67and certain other contexts. These are the conversions
68assignments can do:
69</p>
70<ul>
71<li> Converting any numeric type to any other numeric type.
72
73</li><li> Converting <code>void *</code> to any other pointer type
74(except pointer-to-function types).
75
76</li><li> Converting any other pointer type to <code>void *</code>.
77(except pointer-to-function types).
78
79</li><li> Converting 0 (a null pointer constant) to any pointer type.
80
81</li><li> Converting any pointer type to <code>bool</code>. (The result is
821 if the pointer is not null.)
83
84</li><li> Converting between pointer types when the left-hand target type is
85upward compatible with the right-hand target type. See <a href="Compatible-Types.html">Compatible Types</a>.
86</li></ul>
87
88<p>These type conversions occur automatically in certain contexts,
89which are:
90</p>
91<ul>
92<li> An assignment converts the type of the right-hand expression
93to the type wanted by the left-hand expression. For example,
94
95<div class="example">
96<pre class="example">double i;
97i = 5;
98</pre></div>
99
100<p>converts 5 to <code>double</code>.
101</p>
102</li><li> A function call, when the function specifies the type for that
103argument, converts the argument value to that type. For example,
104
105<div class="example">
106<pre class="example">void foo (double);
107foo (5);
108</pre></div>
109
110<p>converts 5 to <code>double</code>.
111</p>
112</li><li> A <code>return</code> statement converts the specified value to the type
113that the function is declared to return. For example,
114
115<div class="example">
116<pre class="example">double
117foo ()
118{
119 return 5;
120}
121</pre></div>
122
123<p>also converts 5 to <code>double</code>.
124</p></li></ul>
125
126<p>In all three contexts, if the conversion is impossible, that
127constitutes an error.
128</p>
129
130
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