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There are lot of occasions, where we might
need to write the same functions for different data types. A favorite
example can be addition of two variables. The variable can be integer,
float or double. The requirement will be to return the corresponding
return type based on the input type. If we start writing one function
for each of the data type, then we will end up with 4 to 5 different
functions, which can be a night mare for maintenance.
C++ templates come to our rescue in
such situations. When we use C++ function templates, only one function
signature needs to be created. The C++ compiler will automatically
generate the required functions for handling the individual data types.
This is how a programmer's life is made a lot easier.
C++ Template functions - Details:
Let us assume a small example for Add
function. If the requirement is to use this Add function for both
integer and float, then two functions are to be created for each of the
data type (overloading).
int Add(int a,int b) { return a+b;} //
function Without C++ template
float Add(float a, float b) { return
a+b;} // function Without C++ template
If there are some more data types to be
handled, more functions should be added.
But if we use a c++ function template,
the whole process is reduced to a single c++ function template. The
following will be the code fragment for Add function.
template
T Add(T a, T b) //C++ function template
sample
{
return a+b;
}
This c++ function template definition
will be enough. Now when the integer version of the function, the
compiler generates an Add function compatible for integer data type and
if float is called it generates float type and so on.
Here T is the typename. This is
dynamically determined by the compiler according to the parameter
passed. The keyword class means, the parameter can be of any type. It
can even be a class.
C++ Template functions -
Applicability:
C++ function templates can be used
wherever the same functionality has to be performed with a number of
data types. Though very useful, lots of care should be taken to test the
C++ template functions during development. A well written c++ template
will go a long way in saving time for programmers.
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