bugprone-shared-ptr-array-mismatch¶
Finds initializations of C++ shared pointers to non-array type that are initialized with an array.
If a shared pointer std::shared_ptr<T>
is initialized with a new-expression
new T[]
the memory is not deallocated correctly. The pointer uses plain
delete
in this case to deallocate the target memory. Instead a delete[]
call is needed. A std::shared_ptr<T[]>
calls the correct delete operator.
The check offers replacement of shared_ptr<T>
to shared_ptr<T[]>
if it
is used at a single variable declaration (one variable in one statement).
Example:
std::shared_ptr<Foo> x(new Foo[10]); // -> std::shared_ptr<Foo[]> x(new Foo[10]);
// ^ warning: shared pointer to non-array is initialized with array [bugprone-shared-ptr-array-mismatch]
std::shared_ptr<Foo> x1(new Foo), x2(new Foo[10]); // no replacement
// ^ warning: shared pointer to non-array is initialized with array [bugprone-shared-ptr-array-mismatch]
std::shared_ptr<Foo> x3(new Foo[10], [](const Foo *ptr) { delete[] ptr; }); // no warning
struct S {
std::shared_ptr<Foo> x(new Foo[10]); // no replacement in this case
// ^ warning: shared pointer to non-array is initialized with array [bugprone-shared-ptr-array-mismatch]
};
This check partially covers the CERT C++ Coding Standard rule
MEM51-CPP. Properly deallocate dynamically allocated resources
However, only the std::shared_ptr
case is detected by this check.