Is it preferred/okay to use structure-initialization ({...}) over memset, etc.?

The second code you show,

WINDOWPLACEMENT wplcmt;memset(&wplcmt, 0, sizeof(WINDOWPLACEMENT));wplcmt.length = sizeof(WINDOWPLACEMENT);

is beyond horrible. Obfuscation, inefficiency, verbosity, you crammed it all into that.

The first code snippet,

WINDOWPLACEMENT wplcmt = {sizeof(WINDOWPLACEMENT)};

is, except for the obfuscation, the preferred way, unless you want to

• spend more time needlessly writing more code,

• have readers spending more time reading and needlessly analyzing your verbose code,

• get less efficient execution, and

• provide bug entry portals.

By the way, what's with the obfuscated name you used, wplcmt?

Why are you obfuscating names?

Is your question real or is it simply trolling?

Cheers & hth.,

EDIT: the question has been edited. The above questions were in response to the original title/question, "How evil is this structure allocation?". I'm leaving my answer as-is to provide context for the comments.

EDIT 2: the context has changed even further: the OP's nick changed from "Madman" to "Coder". So, while the original was about "How eveil is" normal code by "Madman", it's now about "Is it preferred..." by "Coder". Oh well, I mean, I'm not calling him "Madman" in the commentary, as it would appear now; it's what he called himself, his nick at the time.

Use memset. Then everyone immediately sees what the code does and it's very unlikely to have any unexpected side-effects.

This kind of initialization I fight with constantly. In C99 one can do:

WINDOWPLACEMENT wplcmt = {.length = sizeof(wplcmt), .showCmd = SW_SHOW};

And the other values are zero-initialized.

In G++ you can do:

WINDOWPLACEMENT wplcmt = {length: sizeof(wplcmt), showCmd: SW_SHOW};

And lastly in C++, you can choose between initializing all members, or hope that you get the member order right like this:

WINDOWPLACEMENT wplcmt = {sizeof(wplcmt)};WINDOWPLACEMENT wplcmt = {sizeof(wplcmt), 0, SW_SHOW, {0, 0}, {0, 0}, {0, 0, 0, 0}};

In fact in this last case, I'm not even sure all C++ compilers support compound literal initialization. Furthermore If the members change order, or type, and your values still fit you won't get an error.

Personally I choose to use C99 where I can, I would declare the struct you've given in one hit, with all the known values up front like this:

WINDOWPLACEMENT const wplcmt = {.length = sizeof(wplcmt), .showCmd = SW_SHOW};

Update0

It would seem that the "initialize all" I referred to is only for arrays? My mistake, this makes C++ slightly more usable.