C Inline Function

1. What is an Inline Function?

• An inline function suggests to the compiler to replace the function call with the function code itself.

• This can reduce function call overhead and increase performance for small functions.

• Declared using the inline keyword.

Syntax:

Note: inline is a request to the compiler, not a command. The compiler may ignore it.

2. Example of Inline Function

Output:

• Instead of calling add(), the compiler may replace it with x + y in the code.

3. When to Use Inline Functions

• Inline functions are suitable for small, frequently called functions.

• Examples:

  • Getters/setters

  • Simple calculations

  • Tiny utility functions

Avoid inline for:

• Large functions (increases code size)

• Functions with loops, recursion, or complex logic

4. Inline Function vs Macro

Example using Macro vs Inline Function

Output:

Inline functions are type-safe and generally preferred over macros.

5. Key Points About Inline Functions

1. Declared using inline keyword.

2. Reduces function call overhead.

3. Best for small, frequently used functions.

4. Safer and type-checked compared to macros.

5. Compiler may ignore the inline request if optimization isn’t suitable.