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copied!<p><code>t</code> is pointing to a <em>string literal</em> it is undefined behavior to modify a <em>string literal</em>. The C++ draft standard section <code>2.14.5</code> <em>String literals</em> paragraph <em>12</em> says(<em>emphasis mine</em>):</p> <blockquote> <p>Whether all string literals are distinct (that is, are stored in nonoverlapping objects) is implementation defined. <strong>The effect of attempting to modify a string literal is undefined</strong>.</p> </blockquote> <p>The relevant section from the C99 draft standard is <code>6.4.5</code> <em>String literals</em> paragraph <em>6</em> which says(<em>emphasis mine</em>):</p> <blockquote> <p>It is unspecified whether these arrays are distinct provided their elements have the appropriate values. <strong>If the program attempts to modify such an array, the behavior is undefined.</strong></p> </blockquote> <p>On a typical modern Unix platform you will find <em>string literals</em> in the read-only segment which would result in a access violation if we attempt to modify it. We can use <em>objdump</em> to inspect the read-only section as follows:</p> <pre><code>objdump -s -j .rodata </code></pre> <p>we can see in the following <a href="http://coliru.stacked-crooked.com/a/95f61a4fe4a19155" rel="nofollow">live example</a> that the string literal will indeed be found in the <em>read-only</em> section. Note that I had to add a <code>printf</code> otherwise the compiler would optimize out the string literal. Sample `<em>objdump</em> output:</p> <pre><code>Contents of section .rodata: 400668 01000200 776f726c 64002573 0a00 ....world.%s.. </code></pre> <p>An alternative approach would be to have <code>t</code> point to an array with a copy of a <em>string literal</em> like so:</p> <pre><code>char r[] = "world"; char *const t = r ; </code></pre>

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