How do I interoperate with C APIs std::optional in C++?

This guide explains how to interoperate with C APIs using `std::optional` in C++. It provides insights and examples to effectively handle optional values when interacting with C code.
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#include <iostream> #include <optional> // C function that returns a pointer to an integer or NULL extern "C" int* get_value() { static int value = 42; return &value; // Return address of value // return nullptr; // Simulate no value } // C++ function using std::optional std::optional getOptionalValue() { int* valuePtr = get_value(); if (valuePtr) { return *valuePtr; // Wrap result in std::optional } return std::nullopt; // Return nullopt if no value } int main() { auto optionalValue = getOptionalValue(); if (optionalValue) { std::cout << "Value: " << *optionalValue << std::endl; } else { std::cout << "No value returned" << std::endl; } return 0; }

interoperate C APIs std::optional C++ optional values example

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