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The assignment ipp = &ip is unsafe not safe because it would allow allows the valid code that follows to reference the value of the volatile object i through the non-volatile-qualified reference ip. In this example, the compiler may optimize out the entire if block because i != 0 must be false if i is not volatile.
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This example compiles without warning on Microsoft Visual Studio 2013 when compiled in C mode (/TC) but causes errors when compiled in C++ mode (/TP).
GCC 4.8.1 generates a warning but compiles successfully.
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