Android NDK CMake uses C++17

Android NDK CMake and C++17

The Android NDK (Native Development Kit) provides tools for developing native applications for Android using languages like C and C++. While the NDK traditionally supported C++11 features, recent updates have introduced support for the powerful C++17 standard. This article explores how to leverage C++17 features within your Android NDK projects using CMake.

Understanding C++17

C++17 represents a significant advancement in the C++ language, offering a wealth of new features that enhance code efficiency, readability, and performance. Some key features include:

Key C++17 Features

• Structured bindings: Simplified extraction of values from tuples, structs, and arrays.
• constexpr if: Compile-time conditional statements for more efficient code.
• std::optional: A type-safe way to represent optional values, preventing null pointer errors.
• std::variant: A type-safe union, allowing you to store different types in a single object.
• Improved string handling: Enhancements to string literals and manipulation functions.

Enabling C++17 in Your CMake Project

To utilize C++17 features in your Android NDK project using CMake, you need to configure your build system accordingly.

CMake Configuration

Within your CMakeLists.txt file, add the following lines to enable C++17 support:

cmake_minimum_required(VERSION 3.10)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

Example: Using std::optional

Let’s illustrate how to leverage a C++17 feature, std::optional, within your Android NDK project:

#include 
#include 

int main() {
    std::optional value = 42; // Initialize with a value

    if (value.has_value()) {
        std::cout << "Value is present: " << *value << std::endl;
    } else {
        std::cout << "Value is not present" << std::endl;
    }

    value.reset(); // Reset the value to empty

    if (value.has_value()) {
        std::cout << "Value is present: " << *value << std::endl;
    } else {
        std::cout << "Value is not present" << std::endl;
    }

    return 0;
}

Value is present: 42
Value is not present

Benefits of Using C++17 in Android NDK

Increased Code Clarity and Efficiency

C++17 features, such as structured bindings and constexpr if, streamline code syntax and improve compiler optimization opportunities. This translates to cleaner, more concise, and potentially faster code.

Enhanced Error Handling

Types like std::optional and std::variant provide robust mechanisms for handling optional values and data of multiple types, reducing the likelihood of runtime errors related to null pointers and incorrect type usage.

Improved Code Modernization

Leveraging modern C++ features allows you to write code that is more aligned with current best practices, making your projects easier to maintain and extend in the long run.

Compatibility Considerations

NDK Version

To fully utilize C++17, ensure you are working with a recent version of the Android NDK (NDK r21 and above). Older versions may have limited or no support for C++17 features.

Compiler Support

The compiler used to build your project must support C++17. The default NDK compilers are generally kept up to date to support the latest language standards.

Conclusion

Adopting C++17 within your Android NDK CMake projects opens up opportunities to write more modern, efficient, and error-resistant native code. By enabling C++17 support and incorporating its powerful features, you can significantly enhance the quality and performance of your Android applications.