Inline functions
- 1. NAME: DHWANI HINGORANI ENR NO: 170410107025 SUBJECT: OBJECT ORIENTED PROGRAMMING WITH C++ INLINE FUNCTIONS
- 2. INLINE FUNCTIONS The inline functions are a C++ enhancement feature to increase the execution time of a program. Functions can be instructed to compiler to make them inline so that compiler can replace those function definition wherever those are being called. Compiler replaces the definition of inline functions at compile time instead of referring function definition at runtime.
- 3. ::-EXAMPLE-:: Class A { Public: inline int add(int a, int b) { return (a + b); }; } Class A { Public: int add(int a, int b); }; inline int A::add(int a, int b) { return (a + b); }
- 4. PROS OF INLINE FUNCTIONS 1. It speeds up your program by avoiding function calling overhead. 2. It save overhead of variables push/pop on the stack, when function calling happens. 3. It save overhead of return call from a function. 4. It increases locality of reference by utilizing instruction cache. 5. By marking it as inline, you can put a function definition in a header file (i.e. it can be included in multiple compilation unit, without the linker complaining)
- 5. CONS OF INLINE FUNCTIONS 1. It increases the executable size due to code expansion. 2. C++ inlining is resolved at compile time. Which means if you change the code of the inlined function, you would need to recompile all the code using it to make sure it will be updated. 3. When used in a header, it makes your header file larger with information which users don’t care. 4. As mentioned above it increases the executable size, which may cause thrashing in memory. More number of page fault bringing down your program performance. 5. Sometimes not useful for example in embedded system where large executable size is not preferred at all due to memory constraints.
- 6. WHEN TO USE? Function can be made as inline as per programmer need. Some useful recommendation are mentioned below- 1. Use inline function when performance is needed. 2. Use inline function over macros. 3. Prefer to use inline keyword outside the class with the function definition to hide implementation details.
- 7. THANK YOU!