On Tuesday, 12 January 2016 at 16:20:10 UTC, naptime wrote:
Hello,
I already know the answer to my question, but I would like
someone to reassure me that I'm not mistaken before I rename
literally hundreds of identifiers in my code (and refactor at
least two large templates).
TL;DR: Am I understanding correctly that "_Foo" is NOT
reserved as an identifier in the sense that "__foo" IS
reserved, since they both are reserved in C?
I have been using D for about two years. Before that, I wrote
everything in strict ANSI C. In C, not only are identifies
beginning with two underscores reserved (e.g. __foo), but
identifiers beginning with a single underscore followed by a
capital letter are also reserved (e.g. _Foo)†. I would like to
verify that this is not the case in D. To be absolutely clear,
I already know that such identifiers compile; I want to know if
they are reserved for future use by the D language.
The following quote is from:
https://dlang.org/spec/lex.html#Identifier
Quote:
"Identifiers start with a letter, _, or universal alpha, and
are followed by any number of letters, _, digits, or universal
alphas. Universal alphas are as defined in ISO/IEC 9899:1999(E)
Appendix D. (This is the C99 Standard.) Identifiers can be
arbitrarily long, and are case sensitive. Identifiers starting
with __ (two underscores) are reserved."
The above quote makes it perfectly clear that identifiers
beginning with an underscore followed by an uppercase letter
are not reserved, but I could not find an example of such in
object.d, DRuntime, nor in Phobos2 source (my usual method of
verification). Could someone who knows for sure please verify
that "_Foo" is not reserved in D?
Thank you for your patience, and in advance for any assistance!
†(, as well as some other obscure restrictions e.g.
all-uppercase identifiers beginning with 'E' are reserved in C.)
Yes, symbols in the form of `_Foo` are not reserved in D. Only
symbols beginning with two underscores, such as __traits or
__gshared. Technically the different `op*` names such as opCat,
opBinary, etc. are reserved as well, int he sense that the
compiler will recognize them and do special things, such as
writing a + b as a.opBinary!"+"(b).
