C++ code crashing when using function instead of inline code - c++

Question

C++ rookie here.
I have the following code:
std::vector<float> MyBuffer::readAverage(int numberOfBuffers) {
std::vector<float> result = std::vector<float>(streams.size());
for (int i = 0; i < streams.size(); ++i) {
result[i] = getAverage(streams[i], numberOfBuffers);
}
return result;
}
float MyBuffer::getAverage(std::deque<float> input, int numberOfBuffers) {
float sum = 0;
for (int i = 0; i < numberOfBuffers; ++i) {
sum += input[i];
}
return sum / numberOfBuffers;
}
This code randomly crashes at getAverage(), I am not sure why.
Strange thing (for me as a C++ rookie at least) is that when I inline the function, it does not crash:
std::vector<float> MyBuffer::readAverage(int numberOfBuffers) {
std::vector<float> result = std::vector<float>(streams.size());
for (int i = 0; i < streams.size(); ++i) {
float sum = 0;
for (int i1 = 0; i1 < numberOfBuffers; ++i1) {
sum += streams[i][i1];
}
result[i] = sum / numberOfBuffers;
}
return result;
}
I can understand that there may be many reasons why this specific code is crashing - so my question relates more to what changes when I inline it, rather than calling a function? In my mind it should be exactly the same thing, but I guess there is something about the way C++ works that I am not grasping?

Answer 1

The program has many potential reasons why it can cause a crash.
bufferDurationMs is not initialized in the provided code, I hope its initialized to value other than 0.
for (int i = 0; i < streams.size(); ++i) {
result[i] = getAverage(streams[i], numberOfBuffers); } use result.size() instead of streams.size() as result is lvalue. It
is better to check both of these conditions in for.
It is quite possible that numberOfBuffers can be 0 in which case code would crash(divide by zero)
Some optimizations that can be done in the code:
std::vector<float> result = std::vector<float>(streams.size()); use reserve rather than using a costly operation of creating a
vector and assigning it to lvalue.
std::vector result; result.reserve(streams.size());
float MyBuffer::getAverage(std::deque<float> input, int numberOfBuffers) prefer const reference rather than creating a copy
of an object
const std::deque& input