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| <h3 class="section">6.21 Non-Lvalue Arrays May Have Subscripts</h3> |
| |
| <p><a name="index-subscripting-2304"></a><a name="index-arrays_002c-non_002dlvalue-2305"></a> |
| <a name="index-subscripting-and-function-values-2306"></a>In ISO C99, arrays that are not lvalues still decay to pointers, and |
| may be subscripted, although they may not be modified or used after |
| the next sequence point and the unary ‘<samp><span class="samp">&</span></samp>’ operator may not be |
| applied to them. As an extension, GCC allows such arrays to be |
| subscripted in C90 mode, though otherwise they do not decay to |
| pointers outside C99 mode. For example, |
| this is valid in GNU C though not valid in C90: |
| |
| <pre class="smallexample"> struct foo {int a[4];}; |
| |
| struct foo f(); |
| |
| bar (int index) |
| { |
| return f().a[index]; |
| } |
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