Comparison of C++ templates and generics?

The difference between templates and generics in C++: Templates: defined at compile time, clearly typed, high efficiency, and small code size. Generics: runtime typing, abstract interface, provides flexibility, low efficiency.

Comparison of C++ templates and generics

Concept

• Template: Code block defined at compile time, which can generate different codes according to specific data types.
• Generics: An abstract interface where code can operate on different types of data, typed at runtime.

Difference

##FeatureTemplateGenericDefinition timingCompile timeRun timeTypedClearInferenceEfficiencyFasterSlowerCode sizeSmallerSmaller##Practical case

Template:

template<typename T>
T max(T a, T b) {
  return (a > b) ? a : b;
}

This template function can calculate the maximum value of different types of data, for example:

int max_int = max(10, 20); // 输出：20
double max_double = max(3.14, 2.71); // 输出：3.14

Generic:

class NumberComparator {
public:
  bool operator()(int a, int b) const {
    return a < b;
  }
};

This generic class implements an interface for comparing integers and can be used for different sorting algorithms:

std::vector<int> numbers = {5, 2, 8, 3, 1};
std::sort(numbers.begin(), numbers.end(), NumberComparator());

for (auto& number : numbers) {
  std::cout << number << " "; // 输出：1 2 3 5 8
}

Conclusion

Templates and generics are powerful C++ features, Code for handling different data types. Templates are typed at compile time, making them more efficient and smaller in code size. Generics perform type inference at runtime and provide a more abstract interface, but are slightly less efficient.

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