On 31.05.2017 4:09, Alistair Leslie-Hughes wrote:
+typedef struct _mfmedaitype +{
- IMFMediaType IMFMediaType_iface;
- LONG ref;
+} mfmedaitype;
You got a typo in structure name.
On 31 May 2017 at 04:47, Nikolay Sivov bunglehead@gmail.com wrote:
On 31.05.2017 4:09, Alistair Leslie-Hughes wrote:
+typedef struct _mfmedaitype +{
- IMFMediaType IMFMediaType_iface;
- LONG ref;
+} mfmedaitype;
You got a typo in structure name.
If everyone is going to comment, I might as well join in.
What is the purpose of the typedef?
Hi Henri,
If everyone is going to comment, I might as well join in.
What is the purpose of the typedef?
The purpose is to make a type. For example without it every time we needed to use it we would have to use "struct _mfmediatype name", but with the typedef we can shorthand it to "mfmediatype name".
Best Regards Alistair.
On 3 June 2017 at 03:13, Alistair Leslie-Hughes leslie_alistair@hotmail.com wrote:
The purpose is to make a type. For example without it every time we needed to use it we would have to use "struct _mfmediatype name", but with the typedef we can shorthand it to "mfmediatype name".
That's a rather poor justification for using typedefs, but unfortunately also a really common one. What you're essentially doing is obfuscating the fact that something is a structure/enum/integer/pointer/etc., only to avoid a few keystrokes. One of the reasons that's odd is that the time spent typing in the code should be small compared to the time spent thinking about the problem you're trying to solve.
That's not to say there's never a legitimate reason to use a typedef though. For example, a certain type may be implemented as a 32-bit integer on one platform, a 64-bit integer on another, and a structure on others. A typedef can be used to abstract between those by creating an opaque type, like e.g. time_t. Such cases should be rare however.
On 05.06.2017 17:28, Henri Verbeet wrote:
On 3 June 2017 at 03:13, Alistair Leslie-Hughes leslie_alistair@hotmail.com wrote:
The purpose is to make a type. For example without it every time we needed to use it we would have to use "struct _mfmediatype name", but with the typedef we can shorthand it to "mfmediatype name".
That's a rather poor justification for using typedefs, but unfortunately also a really common one. What you're essentially doing is obfuscating the fact that something is a structure/enum/integer/pointer/etc., only to avoid a few keystrokes. One of the reasons that's odd is that the time spent typing in the code should be small compared to the time spent thinking about the problem you're trying to solve.
That justification is not really strong either. I don't see how using them makes code you're commenting any less readable. When it comes to personal preferences, in case of COM objects, the object name is often a public typedef from coclass declaration (although not in case of this particular type). Although there is no technical reason to use different declarations, I'd argue that it's the most intuitive choice.
That said, there are different preferences. Alistair chose a declaration consistent with existing code within DLL, so I'd say he did the right choice.
Jacek
-
Alistair Leslie-Hughes -
Henri Verbeet -
Jacek Caban -
Nikolay Sivov