1 / 8

Chapter 1 C++ Templates

Chapter 1 C++ Templates. Sections 1.6 and 1.7. Templates. Type-independent patterns that can work with multiple data types Generic programming Code reusable Function Templates These define logic behind the algorithms that work for multiple data types Class Templates

gamba
Télécharger la présentation

Chapter 1 C++ Templates

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 1C++ Templates Sections 1.6 and 1.7

  2. Templates • Type-independent patterns that can work with multiple data types • Generic programming • Code reusable • Function Templates • These define logic behind the algorithms that work for multiple data types • Class Templates • These define generic class patterns into which specific data types can be plugged in to produce new classes

  3. Function Templates • Algorithms may use the same logic for different data types • Different definitions are written just to deal with different data types • Templates permit a common code, independent of the data type • Templates should be in header files, so that the compiler will know how to generate code when it sees the template used • Examples • Lec4/largest.h/cpp, uselargest.cpp Error with template in the .cpp file $ g++ uselargest.cpp largest.cpp /tmp/ccAg3qmY.o: In function `main': uselargest.cpp:(.text+0x133): undefined reference to `int tlargest<int>(int*, int)' uselargest.cpp:(.text+0x16c): undefined reference to `float tlargest<float>(float*, int)'

  4. Class Templates • Identical code can be used for classes that have data of different types • Examples • Lec4/pair.h, usepair.cpp • Use friend function to access private members (example, for IO) • The approach used in the text is also ok • Note the use of a space between > and > in usepair.cpp • This makes the compiler realize that >> is not a single token 4

  5. An Alternative to friend • Use a public ‘print’ function and an operator that calls it

  6. STL Containers Container: stores other objects Common operations such as: push_back, back, front, [ ], etc Not all operations are defined for all containers Sequence: positions of elements are important Example: vector, list Associative containers: elements are accessed through keys Example: map, set, pair Example Lec4/vlm.cpp for example with vector, list, and map 6

  7. STL Iterators Iterator: like a pointer to elements of a container Used to access elements of a container Popular operators * (dereference), ++, --, ==, != Examining all the elements of a container c.begin() returns an iterator to the first element of container c c.end returns a pointer to one past the end 7

  8. Matrices • C++ library does not provide a matrixclass • Constructor • Creates rows number of zero-sized vectors • Resizes each vector to col elements • Two types of [ ] operators • One for LHS that returns by reference • Another for RHS that returns by constant reference • to[i] = from[i] • So we have two very identical functions • What makes their signatures different?

More Related