1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
.. title:: clang-tidy - cert-dcl58-cpp
cert-dcl58-cpp
==============
Modification of the ``std`` or ``posix`` namespace can result in undefined
behavior.
This check warns for such modifications.
The ``std`` (or ``posix``) namespace is allowed to be extended with (class or
function) template specializations that depend on an user-defined type (a type
that is not defined in the standard system headers).
The check detects the following (user provided) declarations in namespace ``std`` or ``posix``:
- Anything that is not a template specialization.
- Explicit specializations of any standard library function template or class template, if it does not have any user-defined type as template argument.
- Explicit specializations of any member function of a standard library class template.
- Explicit specializations of any member function template of a standard library class or class template.
- Explicit or partial specialization of any member class template of a standard library class or class template.
Examples:
.. code-block:: c++
namespace std {
int x; // warning: modification of 'std' namespace can result in undefined behavior [cert-dcl58-cpp]
}
namespace posix::a { // warning: modification of 'posix' namespace can result in undefined behavior
}
template <>
struct ::std::hash<long> { // warning: modification of 'std' namespace can result in undefined behavior
unsigned long operator()(const long &K) const {
return K;
}
};
struct MyData { long data; };
template <>
struct ::std::hash<MyData> { // no warning: specialization with user-defined type
unsigned long operator()(const MyData &K) const {
return K.data;
}
};
namespace std {
template <>
void swap<bool>(bool &a, bool &b); // warning: modification of 'std' namespace can result in undefined behavior
template <>
bool less<void>::operator()<MyData &&, MyData &&>(MyData &&, MyData &&) const { // warning: modification of 'std' namespace can result in undefined behavior
return true;
}
}
This check corresponds to the CERT C++ Coding Standard rule
`DCL58-CPP. Do not modify the standard namespaces
<https://www.securecoding.cert.org/confluence/display/cplusplus/DCL58-CPP.+Do+not+modify+the+standard+namespaces>`_.
|
