Type Traits (<type_traits>), std::enable_if, and SFINAE0%

Modern C++20 Concepts and Constraints (requires Clause)

Type Traits (<type_traits>), std::enable_if, and SFINAE

Advanced14 min read•Updated: 2026-10-22

🔬 Type Traits, std::enable_if, and SFINAE

Introduction

SFINAE stands for "Substitution Failure Is Not An Error". In C++, if substituting a template parameter causes an invalid type expression, the compiler does not fail compilation; it simply discards that candidate function from the overload set. In C++11/C++14, SFINAE combined with <type_traits> and std::enable_if formed the foundation of compile-time introspection.

🧪 Type Traits Queries at Compile-Time

1#include <iostream>
2#include <type_traits>
3 
4int main() {
5    std::cout << std::boolalpha;
6    std::cout << "Is int integral?     " << std::is_integral<int>::value << "\n";
7    std::cout << "Is double floating?  " << std::is_floating_point<double>::value << "\n";
8    std::cout << "Is pointer?          " << std::is_pointer<int*>::value << "\n";
9    return 0;
10}

🛡️ SFINAE with `std::enable_if_t`

1#include <iostream>
2#include <type_traits>
3 
4// Overload active ONLY for integral types (int, long, short):
5template <typename T>
6std::enable_if_t<std::is_integral_v<T>, void> processData(T value) {
7    std::cout << "[INTEGER LOGIC]: " << (value * 2) << "\n";
8}
9 
10// Overload active ONLY for floating point types (float, double):
11template <typename T>
12std::enable_if_t<std::is_floating_point_v<T>, void> processData(T value) {
13    std::cout << "[FLOAT LOGIC]:   " << (value / 2.0) << "\n";
14}
15 
16int main() {
17    processData(10);   // Routes to integral overload
18    processData(4.5);  // Routes to floating overload
19    // processData("MSK"); // 💥 SFINAE fails on both: Compiler halts with clean error!
20    return 0;
21}

Next Lesson

Modern C++20 Concepts and Constraints (requires Clause)

Continue learning with hands-on practice, examples, and exercises in the upcoming topic.

Related Lessons

Previous Lesson	Next Lesson
Variadic Templates and Fold Expressions in Modern C++	Modern C++20 Concepts and Constraints (requires Clause)

Practice Quiz

Test your understanding of this lesson with 1 questions. Each question has one correct answer.

Previous Next

PreviousPrevNext

MSK Institute • Shikohabad

Loading Page Content...

Preparing courses, live labs, and learning resources.सामग्री लोड हो रही है, कृपया प्रतीक्षा करें...

Connecting serverPlease wait...

💻 Practical Labs🚀 Free Demo📜 Verified Certificates

Modern C++20 Concepts and Constraints (requires Clause)

Type Traits (<type_traits>), std::enable_if, and SFINAE

Advanced14 min read•Updated: 2026-10-22

Study Materials

🔬 Type Traits, std::enable_if, and SFINAE

Introduction

🧪 Type Traits Queries at Compile-Time

1#include <iostream>
2#include <type_traits>
3 
4int main() {
5    std::cout << std::boolalpha;
6    std::cout << "Is int integral?     " << std::is_integral<int>::value << "\n";
7    std::cout << "Is double floating?  " << std::is_floating_point<double>::value << "\n";
8    std::cout << "Is pointer?          " << std::is_pointer<int*>::value << "\n";
9    return 0;
10}

🛡️ SFINAE with `std::enable_if_t`

1#include <iostream>
2#include <type_traits>
3 
4// Overload active ONLY for integral types (int, long, short):
5template <typename T>
6std::enable_if_t<std::is_integral_v<T>, void> processData(T value) {
7    std::cout << "[INTEGER LOGIC]: " << (value * 2) << "\n";
8}
9 
10// Overload active ONLY for floating point types (float, double):
11template <typename T>
12std::enable_if_t<std::is_floating_point_v<T>, void> processData(T value) {
13    std::cout << "[FLOAT LOGIC]:   " << (value / 2.0) << "\n";
14}
15 
16int main() {
17    processData(10);   // Routes to integral overload
18    processData(4.5);  // Routes to floating overload
19    // processData("MSK"); // 💥 SFINAE fails on both: Compiler halts with clean error!
20    return 0;
21}

Next Lesson

Modern C++20 Concepts and Constraints (requires Clause)

Continue learning with hands-on practice, examples, and exercises in the upcoming topic.

Related Lessons

Previous Lesson	Next Lesson
Variadic Templates and Fold Expressions in Modern C++	Modern C++20 Concepts and Constraints (requires Clause)

Practice Quiz

Test your understanding of this lesson with 1 questions. Each question has one correct answer.

Previous Next

🔬 Type Traits, std::enable_if, and SFINAE

Introduction

🧪 Type Traits Queries at Compile-Time

🛡️ SFINAE with std::enable_if_t

Modern C++20 Concepts and Constraints (requires Clause)

Related Lessons

Practice Quiz

Loading Page Content...

🔬 Type Traits, std::enable_if, and SFINAE

Introduction

🧪 Type Traits Queries at Compile-Time

🛡️ SFINAE with std::enable_if_t

Modern C++20 Concepts and Constraints (requires Clause)

Related Lessons

Practice Quiz

🛡️ SFINAE with `std::enable_if_t`

🛡️ SFINAE with `std::enable_if_t`