Contents
V570. Variable is assigned to itself.
The analyzer has detected a potential error: a variable is assigned to itself.
The example:
dst.m_a = src.m_a;
dst.m_b = dst.m_b;The dst.m_b variable value remains unchanged because of a typo.
The fixed code:
dst.m_a = src.m_a;
dst.m_b = src.m_b;The analyzer issues a warning not only for copy assignment but also for move assignment.
dst.m_a = std::move(src.m_a);The analyzer does not issue the warning every time it detects assignment of a variable to itself. For example, if the variables are enclosed in parentheses. This method is often used to suppress compiler-generated warnings.
The example:
int Foo(int foo)
{
UNREFERENCED_PARAMETER(foo);
return 1;
}The UNREFERENCED_PARAMETER macro is defined in the WinNT.h file in the following way:
#define UNREFERENCED_PARAMETER(P) \
{ \
(P) = (P); \
}The analyzer recognizes such cases and does not issue the V570 warning for assignment like this:
(foo) = (foo);If this approach is not used in the project, add the following comment to enable the warning:
//V_WARN_ON_ARGUMENT_SELF_ASSIGNNote. If the V570 warning is issued for macros that cannot be changed, use macro suppression via adding special comment in a common project file (for instance, StdAfx.h).
The example:
//-V:MY_MACROS:V570This diagnostic is classified as:
You can look at examples of errors detected by the V570 diagnostic. |
Was this page helpful?
