Namespaces
Variants
Views
Actions

std::numeric_limits

From cppreference.com
 
C++
 
Utilities library
 
Type support
Basic types
Fundamental types
Fixed width integer types (C++11)
Numeric limits
numeric_limits
C numeric limits interface
Runtime type information
Type traits
Primary type categories
is_void(C++11)
is_array(C++11)
is_pointer(C++11)
is_enum(C++11)
is_union(C++11)
is_class(C++11)
is_function(C++11)
is_object(C++11)
is_scalar(C++11)
is_compound(C++11)
is_integral(C++11)
is_floating_point(C++11)
is_fundamental(C++11)
is_arithmetic(C++11)
is_reference(C++11)
is_lvalue_reference(C++11)
is_rvalue_reference(C++11)
is_member_pointer(C++11)
is_member_object_pointer(C++11)
is_member_function_pointer(C++11)
Type properties
is_const(C++11)
is_volatile(C++11)
is_pod(C++11)
is_empty(C++11)
is_polymorphic(C++11)
is_abstract(C++11)
Supported operations
is_constructible
is_trivially_constructible
is_nothrow_constructible		(C++11)
(C++11)
(C++11)
is_default_constructible
is_trivially_default_constructible
is_nothrow_default_constructible		(C++11)
(C++11)
(C++11)
is_copy_constructible
is_trivially_copy_constructible
is_nothrow_copy_constructible		(C++11)
(C++11)
(C++11)
is_move_constructible
is_trivially_move_constructible
is_nothrow_move_constructible		(C++11)
(C++11)
(C++11)
is_assignable
is_trivially_assignable
is_nothrow_assignable		(C++11)
(C++11)
(C++11)
is_copy_assignable
is_trivially_copy_assignable
is_nothrow_copy_assignable		(C++11)
(C++11)
(C++11)
is_move_assignable
is_trivially_move_assignable
is_nothrow_move_assignable		(C++11)
(C++11)
(C++11)
is_destructible
is_trivially_destructible
is_nothrow_destructible		(C++11)
(C++11)
(C++11)
has_virtual_destructor(C++11)
Relationships and property queries
is_same(C++11)
is_base_of(C++11)
is_convertible(C++11)
alignment_of(C++11)
rank(C++11)
extent(C++11)
Type modifications
remove_cv
remove_const
remove_volatile		(C++11)
(C++11)
(C++11)
add_cv
add_const
add_volatile		(C++11)
(C++11)
(C++11)
make_signed(C++11)
make_unsigned(C++11)
Type transformations
aligned_storage(C++11)
aligned_union(C++11)
decay(C++11)
enable_if(C++11)
conditional(C++11)
common_type(C++11)
underlying_type(C++11)
result_of(C++11)
Type trait constants
integral_constant(C++11)
 
std::numeric_limits
Static constants
numeric_limits::is_specialized
numeric_limits::is_signed
numeric_limits::is_integer
numeric_limits::is_exact
numeric_limits::has_infinity
numeric_limits::has_quiet_NaN
numeric_limits::has_signaling_NaN
numeric_limits::has_denorm
numeric_limits::has_denorm_loss
numeric_limits::round_style
numeric_limits::is_iec559
numeric_limits::is_bounded
numeric_limits::is_modulo
numeric_limits::digits
numeric_limits::digits10
numeric_limits::max_digits10(C++11)
numeric_limits::radix
numeric_limits::min_exponent
numeric_limits::min_exponent10
numeric_limits::max_exponent
numeric_limits::max_exponent10
numeric_limits::traps
numeric_limits::tinyness_before
Static member functions
numeric_limits::min
numeric_limits::lowest(C++11)
numeric_limits::max
numeric_limits::epsilon
numeric_limits::round_error
numeric_limits::infinity
numeric_limits::quiet_NaN
numeric_limits::signaling_NaN
numeric_limits::denorm_min
Helper types
float_round_style
float_denorm_style
 
Defined in header <limits>
template< class T > class numeric_limits;

The numeric_limits class template provides a standardized way to query about various properties of representation of fundamental types. This information is provided via specializations of the numeric_limits template. The standard library makes available specializations for all fundamental types.

Defined in header <limits>
template<> class numeric_limits<bool>;

template<> class numeric_limits<char>;
template<> class numeric_limits<signed char>;
template<> class numeric_limits<unsigned char>;
template<> class numeric_limits<wchar_t>;
template<> class numeric_limits<char16_t>;   // C++11 feature
template<> class numeric_limits<char32_t>;   // C++11 feature
template<> class numeric_limits<short>;
template<> class numeric_limits<unsigned short>;
template<> class numeric_limits<int>;
template<> class numeric_limits<unsigned int>;
template<> class numeric_limits<long>;
template<> class numeric_limits<unsigned long>;
template<> class numeric_limits<long long>;
template<> class numeric_limits<unsigned long long>;
template<> class numeric_limits<float>;
template<> class numeric_limits<double>;

template<> class numeric_limits<long double>;

Additionally, a specialization exists for every cv-qualified version of each fundamental type, identical to the unqualified specialization, e.g. std::numeric_limits<const int>, std::numeric_limits<volatile int>, and std::numeric_limits<const volatile int> are provided and are equivalent to std::numeric_limits<int>.

The standard library types that are aliases of fundamental types (such as std::size_t or std::streamsize may also be examined with the std::numeric_limits type traits.

Implementations may provide specializations of std::numeric_limits for implementation-specific types: e.g. GCC provides std::numeric_limits<__int128>. Libraries may add specializations for library-provided types, e.g. OpenEXR provides std::numeric_limits<half> for a 16-bit floating-point type.

Contents

[edit] Member constants

[static]
 identifies types for which std::numeric_limits is specialized
(public static member constant) [edit]
[static]
 identifies signed types
(public static member constant) [edit]
[static]
 identifies integer types
(public static member constant) [edit]
[static]
 identifies exact types
(public static member constant) [edit]
[static]
 identifies floating-point types that can represent the special value "positive infinity"
(public static member constant) [edit]
[static]
 identifies floating-point types that can represent the special value "quiet not-a-number" (NaN)
(public static member constant) [edit]
[static]
 identifies floating-point types that can represent the special value "signaling not-a-number" (NaN)
(public static member constant) [edit]
[static]
 identifies the denormalization style used by the floating-point type
(public static member constant) [edit]
[static]
 identifies the floating-point types that detect loss of precision as denormalization loss rather than inexact result
(public static member constant) [edit]
[static]
 identifies the rounding style used by the type
(public static member constant) [edit]
[static]
 identifies the IEC 559/IEEE 754 floating-point types
(public static member constant) [edit]
[static]
 identifies types that represent a finite set of values
(public static member constant) [edit]
[static]
 identifies types that handle overflows with modulo arithmetic
(public static member constant) [edit]
[static]
 number of radix digits that can be represented without change
(public static member constant) [edit]
[static]
 number of decimal digits that can be represented without change
(public static member constant) [edit]
[static] (C++11)
 number of decimal digits necessary to differentiate all values of this type
(public static member constant) [edit]
[static]
 the radix or integer base used by the representation of the given type
(public static member constant) [edit]
[static]
 one more than the smallest negative power of the radix that is a valid normalized floating-point value
(public static member constant) [edit]
[static]
 the smallest negative power of ten that is a valid normalized floating-point value
(public static member constant) [edit]
[static]
 one more than the largest integer power of the radix that is a valid finite floating-point value
(public static member constant) [edit]
[static]
 the largest integer power of 10 that is a valid finite floating-point value
(public static member constant) [edit]
[static]
 identifies types which can cause arithmetic operations to trap
(public static member constant) [edit]
[static]
 identifies floating-point types that detect tinyness before rounding
(public static member constant) [edit]

[edit] Member functions

[static]
 returns the smallest finite value of the given type
(public static member function) [edit]
[static] (C++11)
 returns the lowest finite value of the given type
(public static member function) [edit]
[static]
 returns the largest finite value of the given type
(public static member function) [edit]
[static]
 returns the difference between 1.0 and the next representable value of the given floating-point type
(public static member function) [edit]
[static]
 returns the maximum rounding error of the given floating-point type
(public static member function) [edit]
[static]
 returns the positive infinity value of the given floating-point type
(public static member function) [edit]
[static]
 returns a quiet NaN value of the given floating-point type
(public static member function) [edit]
[static]
 returns a signaling NaN value of the given floating-point type
(public static member function) [edit]
[static]
 returns the smallest positive subnormal value of the given floating-point type
(public static member function) [edit]

[edit] Helper classes

 indicates floating-point rounding modes
(enum) [edit]
indicates floating-point denormalization modes
(enum) [edit]

[edit] Relationship with C library macro constants

Specialization Members
min() lowest()
(C++11) 		max() epsilon() digits() digits10() min_exponent() min_exponent10() max_exponent() max_exponent10() radix
numeric_limits< bool > 2
numeric_limits< char > CHAR_MIN CHAR_MIN CHAR_MAX 2
numeric_limits< signed char > SCHAR_MIN SCHAR_MIN SCHAR_MAX 2
numeric_limits< unsigned char > ​0​ ​0​ UCHAR_MAX 2
numeric_limits< wchar_t > WCHAR_MIN WCHAR_MIN WCHAR_MAX 2
numeric_limits< char16_t > ​0​ ​0​ UINT_LEAST16_MAX 2
numeric_limits< char32_t > ​0​ ​0​ UINT_LEAST32_MAX 2
numeric_limits< short > SHRT_MIN SHRT_MIN SHRT_MAX 2
numeric_limits< signed short >
numeric_limits< unsigned short > ​0​ ​0​ USHRT_MAX 2
numeric_limits< int > INT_MIN INT_MIN INT_MAX 2
numeric_limits< signed int >
numeric_limits< unsigned int > ​0​ ​0​ UINT_MAX 2
numeric_limits< long > LONG_MIN LONG_MIN LONG_MAX 2
numeric_limits< signed long >
numeric_limits< unsigned long > ​0​ ​0​ ULONG_MAX 2
numeric_limits< long long > LLONG_MIN LLONG_MIN LLONG_MAX 2
numeric_limits< signed long long >
numeric_limits< unsigned long long > ​0​ ​0​ ULLONG_MAX 2
numeric_limits< float > FLT_MIN -FLT_MAX FLT_MAX FLT_EPSILON FLT_MANT_DIG FLT_DIG FLT_MIN_EXP FLT_MIN_10_EXP FLT_MAX_EXP FLT_MAX_10_EXP FLT_RADIX
numeric_limits< double > DBL_MIN -DBL_MAX DBL_MAX DBL_EPSILON DBL_MANT_DIG DBL_DIG DBL_MIN_EXP DBL_MIN_10_EXP DBL_MAX_EXP DBL_MAX_10_EXP FLT_RADIX
numeric_limits< long double > LDBL_MIN -LDBL_MAX LDBL_MAX LDBL_EPSILON LDBL_MANT_DIG LDBL_DIG LDBL_MIN_EXP LDBL_MIN_10_EXP LDBL_MAX_EXP LDBL_MAX_10_EXP FLT_RADIX
Retrieved from "http://en.cppreference.com/mwiki/index.php?title=cpp/types/numeric_limits&oldid=34932"