...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Safe Numerics 
A type fulfills the requirements of an Integer if it has the properties of a integer.
More specifically, a type T is Integer if there exists a
specialization of std::numeric_limits<T> for which
std::numeric_limits<T>::is_integer
is equal to
true
. See the documentation for standard library class
numeric_limits
. The standard library includes such
specializations for all builtin numeric types. Note that this concept is
distinct from the C++ standard library type traits
is_integral
and is_arithmetic
. These latter
fulfill the requirements of the concept Numeric. But there are types which
fulfill this concept for which is_arithmetic<T>::value ==
false
. For example see safe<int>
.
T, U, V 
A type that is a model of an Integer type 
t, u 
An object of type modeling an Integer type 
OS, IS 
A type that is a model of an output or input stream 
os, is 
An object of a type modeling output or input stream 
In addition to the expressions defined in Integer, the following expression must be true.
Any or all of the following unary operators MAY be defined. Any
such defined operators shall implement the semantics as described
below
Any or all of the following binary operators MAY be defined. Any
defined operators shall implement the semantics as described bellow
Table 6. Binary Operators
Expression  Return Type  Semantics 

t % u 
T 
t modulus u. t can be a Numeric type. 
t << u 
T 
shift t left u bits 
t >> u 
T 
shift t right by u bits 
t & u 
V 
and of t and u padded out to max # bits in t, u 
t  u 
V 
or of t and u padded out to max # bits in t, u 
t ^ u 
V 
exclusive or of t and u padded out to max # bits in t, u 
t <<= u 
T 
left shift the value of t by u bits 
t >>= u 
T 
right shift the value of t by u bits 
t &= u 
T 
and the value of t with u and assign to t 
t = u 
T 
or the value of t with u and assign to t 
t ^= u 
T 
exclusive or the value of t with u and assign to t 
os << t 

write contents of t to output stream 
is >> t 

read contents of an input stream into t 