The goal of this exercise is to get some confidence with the smart pointers
provided by the C++ standard library:
unique_ptr and
shared_ptr.
Exercise 1
In the C language, memory is allocated with malloc and released with free.
Both functions are available also in C++, possibly in namespace std. Consider
c_alloc.cpp,
where a bunch of memory is allocated and released with those functions. Adapt
the code to manage the allocation through a smart pointer with an appropriate
deleter.
Note also the use of
std::span, available since
C++20, to represent a contiguous sequence of objects.
Exercise 2
Open the test program dir.cpp and, following the hints in the file, complete the existing code to:
- create a smart pointer managing a DIR resource obtained with the
opendirfunction call - associate a deleter to that smart pointer
- implement a function to read the names of the files in that
directory, using
readdir_r - check if the deleter is called at the right moment
- hide the creation of the smart pointer behind a factory function
- populate a vector of
FILEs, each properly wrapped in a smart pointer, obtainedfopening the regular files in that directory
You can experiment with both kinds of smart pointers and with the type of the function arguments.