What does (void)result; mean in android OpenSL example?

Question

In the android implementation of OpenSL ES, the following example code can be found in the android-ndk /samples/native-audio/jni/native-audio-jni.c

SLresult result;
result = slCreateEngine(&engineObject, 0, NULL, 0, NULL, NULL);
assert(SL_RESULT_SUCCESS == result);
(void)result;

The SLResult is defined to be of type SLuint32, which by definition is a 32-bit unsigned integer type.

My question is: what does the line (void)result; do? I thought this would do nothing, and a compiler could optimize this away. However, similar line appears in many places in the example, and I am left wondering whether it has some importance after all.

Answer 1

That kind of silly code is sometimes inserted to silence compiler or lint warnings, such as "variable result is not used" when assertion-checking is turned off.

I did not write the code, so I cannot be certain, but that is my guess.