C++ examples for Data Type:constexpr
A constant expression function is a function whose value can be determined by the compiler.
The function must return a value (not void)
The entire body of the function must be a single return statement that returns an expression
The expression must evaluate to a constant after substitution.
Here's a snippet of code that is a valid constant expression:
constexpr double expand(int original) { return original * 1.5; } const int getArraySize(int hours) { return 60 * 60 * hours; } int ticks[getArraySize(24)];
Example,
#include <iostream> constexpr int getArraySize() { return 1024; // ww w . j a va 2 s . c om } int main() { int bolts[getArraySize()]; int boltsSize = sizeof(bolts) / sizeof(bolts[0]); for (int i = 0; i < boltsSize; i++) { bolts[i] = i * boltsSize; } std::cout << "Value of bolts[10]: " << bolts[10] << std::endl; return 0; }