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Subject: Re: [boost] underscores in private class member names (was: [local] this_ or _this?)
From: Stewart, Robert (Robert.Stewart_at_[hidden])
Date: 2011-04-18 10:41:16

Julian Gonggrijp wrote:
> All this talking of underscores makes me wonder about private class
> members. Several authors advise to give them names with a prefix
> underscore (followed by a lowercase letter). It does seem to have
> clear advantages: it visually marks the members as implementation
> details, and it also makes it easier to distinguish class member data
> from arguments and locally declared variables in member functions.
> However, your opinions probably differ wildly on the matter.
> Would you consider it good practice to give private class members a
> name that starts with _[a-z] (regex)?

Distinguishing private data members from local variables and formal parameters is useful. It creates a distinct "namespace" from local variable and formal parameter names. How to mark them is purely subjective. Some use the "m_" prefix, popularized by MFC and MSVC code generators, but I find that to be too much of a wart on the name. Some use "this->" as a prefix, so their data member names need no special marking.

I like to distinguish protected and private data members but with a trailing underscore. I use a trailing underscore because it is less important than the data member's name. (I also use a preceding underscore for formal parameters to give them another "namespace." In that case, the underscore can't be on the end, of course.)

Rob Stewart robert.stewart_at_[hidden]
Software Engineer using std::disclaimer;
Dev Tools & Components
Susquehanna International Group, LLP

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