[cstring.syn] Add example of implicit object creation in memcpy and memmove

Author: Eisenwave

source/strings.tex

@@ -5517,6 +5517,33 @@
 immediately prior to copying the sequence of characters to the destination.
 Each of these functions returns a pointer to a suitable created object, if any,
 otherwise the value of the first parameter.
+\begin{example}
+\begin{codeblock}
+int x = 0;
+memmove(&x, &x, sizeof(int));
+assert(x == 0);                 // Passes.
+
+unsigned y;
+memcpy(&y, &x, sizeof(int));
+assert(y == 0);                 // Passes.
+
+unsigned char bytes[4] = {
+  0xff, 0xff, 0xff, 0xff
+};
+memcpy(&y, bytes, 4);
+assert(y == 0xffffffff);        // Passes, assuming that \tcode{sizeof(unsigned)} equals \tcode{4},
+                                // and that \tcode{CHAR_BIT} equals \tcode{8}.
+\end{codeblock}
+Both \tcode{x} and \tcode{y} are transparently replaced\iref{basic.life}
+with implicitly created objects in the storage of the old objects,
+and refer to the new respective objects.
+In the call to \tcode{memmove},
+the implicit object creation takes place after copying the bytes of \tcode{x}
+into a temporary array,
+and immediately before copying them into the implicitly created object.
+Since \tcode{int} is trivially copyable\iref{basic.types.general},
+\tcode{x} retains the value \tcode{0}.
+\end{example}
 
 \pnum
 \begin{note}