The "lambda$__anon$" identifer is just the name of the local function, it could just as well have been "elephant" or anything else. The first line defines the nested function:
{
double elephant (double x){ return x/3; }
And the second line references that same identifer:
&elephant;
}
Normally an expression that didn't include an assignment call or a function call is legal but doesn't do anything. But as the article mentions, GCC uses it as the return value of the block.
The commenters seem to have identified the undefined behaviour here: the resulting value is a pointer to a function that's only valid within the block but is being used outside it.
What do the dollar signs do? If they're really just part of the identifier it doesn't seem necessary to make sure the compiler supports it, rather than just use a more normal name like elephant.
The "lambda$__anon$" identifer is just the name of the local function, it could just as well have been "elephant" or anything else. The first line defines the nested function:
And the second line references that same identifer: Normally an expression that didn't include an assignment call or a function call is legal but doesn't do anything. But as the article mentions, GCC uses it as the return value of the block.The commenters seem to have identified the undefined behaviour here: the resulting value is a pointer to a function that's only valid within the block but is being used outside it.