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Re: oversensitive "use of cast expressions as lvalues isdeprecated"


Shaun Jackman <sjackman@telus.net> writes:

> The following statement is the result of a macro expansion (hence
> all the extra parenthesis). gcc's giving me a new warning about
> using a casted lvalue. I don't see where there is a casted lvalue
> here. The rhs of the assigment is an rvalue, so I'll ignore
> that. port is casted, but it's an rvalue at this point. Once it's
> dereferenced it's an lvalue, but there's no further casting after
> that. What's gone wrong here?
>
> int port;
> const void* src;
> (*((volatile uint16_t*)(port)) = (*((uint16_t *) src)++));

The casted lvalue is ((uint16_t *) src). The increment operator needs
a proper lvalue.

By the way, accessing nonvolatile objects through a volatile object
pointer is dangerous. It might do what you want, but is not guaranteed
to.

-- 
	Falk


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