= Operator Names =

This page has been created on occasion of the extension of Boost.TypeTraits by operator traits to give an overview over existing naming of operators and related operator-fuctors in the standard and boost libraries. The purpose of the page is to collect differences and support convergence.

||=Column      =||=Comment  =||
||=op          =||The operator sign||
||=alt         =||An alternative tokens, if available ||
||=type_traits =||boost::type_traits naming as proposed by Frédéric Bron (review version). ||
||=**MUP**     =||Most Unifying Proposal ||
||=std         =|| ` =  :`  Equal naming in the standard ||
||=            =|| ` =* :`  Equal naming, new in next standard. ||
||=proto       =|| ` =  :`  Equal naming in boost::proto ||
||=            =|| `*_p :`  Partial equality except for a prefix or suffix ||
||=operator    =||Corresponding naming of concepts from boost::operator ||

The names in column MUP are trying to minimize the differences between names and maximize the naming consistency. The naming from Boost.Proto is found in other boost libraries, e.g. accumulator and phoenix.

||=op    =||=alt       =||= type_traits       =||= **MUP**            =||= std    =||=  proto              =||= boost::operator     =||
||=`==`  =||=          =||equal_to             ||**equal_to**          ||  `=`     ||   `=`                 ||equality_comparable    ||
||=`!=`  =||=`not_eq`  =||not_equal_to         ||**not_equal_to**      ||  `=`     ||   `=`                 ||                       ||
||=`<`   =||=          =||less                 ||**less**              ||  `=`     ||   `=`                 ||less_than_comparable   ||
||=`<=`  =||=          =||less_equal           ||**less_equal**        ||  `=`     ||   `=`                 ||                       ||
||=`>`   =||=          =||greater              ||**greater**           ||  `=`     ||   `=`                 ||                       ||
||=`>=`  =||=          =||greater_equal        ||**greater_equal**     ||  `=`     ||   `=`                 ||                       ||
||=`+`   =||=          =||plus                 ||**plus**              ||  `=`     ||   `=`                 ||addable                ||
||=`-`   =||=          =||minus                ||**minus**             ||  `=`     ||   `=`                 ||subtractable           ||
||=`*`   =||=          =||multiplies           ||**multiplies**        ||  `=`     ||   `=`                 ||multipliable           ||
||=`/`   =||=          =||divides              ||**divides**           ||  `=`     ||   `=`                 ||dividable              ||
||=`%`   =||=          =||modulus              ||**modulus**           ||  `=`     ||   `=`                 ||modable                ||
||=`+=`  =||=          =||plus_equal           ||**plus_assign**       ||          ||  *_assign             ||                       ||
||=`-=`  =||=          =||minus_equal          ||**minus_assign**      ||          ||  *_assign             ||                       ||
||=`*=`  =||=          =||multiplies_equal     ||**multiplies_assign** ||          ||  *_assign             ||                       ||
||=`/=`  =||=          =||divides_equal        ||**divides_assign**    ||          ||  *_assign             ||                       ||
||=`%=`  =||=          =||modulus_equal        ||**modulus_assign**    ||          ||  *_assign             ||                       ||
||=`&&`  =||=`and`     =||logical_and          ||**logical_and**       ||  `=`     ||   `=`                 ||                       ||
||=`||`  =||=`or`      =||logical_or           ||**logical_or**        ||  `=`     ||   `=`                 ||                       ||
||=`&`   =||=`bitand`  =||bit_and              ||**bit_and**           ||  `=`*    ||  bitwise_*            ||andable                ||
||=`|`   =||=`bitor`   =||bit_or               ||**bit_or**            ||  `=`*    ||  bitwise_*            ||orable                 ||
||=`^`   =||=          =||bit_xor              ||**bit_xor**           ||  `=`*    ||  bitwise_*            ||xorable                ||
||=`<<`  =||=          =||left_shift           ||**left_shift**        ||          ||shift_left             ||left_shiftable         ||
||=`>>`  =||=          =||right_shift          ||**right_shift**       ||          ||shift_right            ||right_shiftable        ||
||=`&=`  =||=`and_eq`  =||bit_and_equal        ||**bit_and_assign**    ||          ||bitwise_and_assign     ||                       ||
||=`|=`  =||=`or_eq`   =||bit_or_equal         ||**bit_or_assign**     ||          ||bitwise_or_assign      ||                       ||
||=`^=`  =||=`xor_eq`  =||bit_xor_equal        ||**bit_xor_assign**    ||          ||bitwise_xor_assign     ||                       ||
||=`<<=` =||=          =||left_shift_equal     ||**left_shift_assign** ||          ||shift_left_assign      ||                       ||
||=`>>=` =||=          =||right_shift_equal    ||**right_shift_assign**||          ||shift_right_assign     ||                       ||
||=`++`  =||=          =||prefix_increment     ||**pre_increment**     ||          ||pre_inc                ||incrementable          ||
||=`--`  =||=          =||prefix_decrement     ||**pre_decrement**     ||          ||pre_dec                ||decrementable          ||
||=`+`   =||=          =||unary_plus           ||**unary_plus**        ||          ||   `=`                 ||                       ||
||=`-`   =||=          =||unary_minus          ||**negate**            ||negate    ||negate                 ||                       ||
||=`!`   =||=`not`     =||logical_not          ||**logical_not**       ||  `=`     ||logical_not            ||                       ||
||=`~`   =||=`compl`   =||complement           ||**complement**        ||          ||complement             ||                       ||
||=`*`   =||=          =||dereference          ||**dereference**       ||          ||dereference            ||                       ||
||=`++`  =||=          =||postfix_increment    ||**post_increment**    ||          ||post_inc               ||                       ||
||=`--`  =||=          =||postfix_decrement    ||**post_decrement**    ||          ||post_dec               ||                       ||



There are some conflicts that have been solved under these rationals. 

An name is chosen along these priorities
1. If the name exists in the current c++ standard.
2. If the name exists in the new upcoming c++ standard.
3. Name is not given by 1 or 2 but is used in proto
4. For the remaining conflicts
   a. Does the name follow general boost naming conventions?
   b. Can it be completed to a typical concept name "conceptified". E.g. left_shift -> left_shiftable 

||`o=`      || op_equal vs. op_assign || proto and other boost::libs agree on `op_assign`. We can better conceptify to OpAssignable ||
||          || bit vs. bitwise        || bitwise seems to be more "natural" but some naming in the standard prefers bit_ prefix [[br]] (see http://permalink.gmane.org/gmane.comp.lib.boost.devel/218617) ||
||`<< >>`   || shift_xxx or xxx_shift || goes to xxx_shift, because we can conceptify to xxx_shiftable more nicely. ||
||`++ --`   || pre/postfix vs. pre/post || goes to pre_in/decrement post_in/decrement. Seems simpler and more natural. ||