名前空間
変種
操作

std::numeric_limits::digits10

提供: cppreference.com

 
 
ユーティリティライブラリ
支援を入力します (basic types, RTTI, type traits)
動的なメモリ管理
エラー処理
プログラムユーティリティ
可変個引数関数
日付と時刻
関数オブジェクト
initializer_list(C++11)
bitset
hash(C++11)
関係演算子
Original:
Relational operators
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
rel_ops::operator!=
rel_ops::operator>
rel_ops::operator<=
rel_ops::operator>=
ペアとタプル
Original:
Pairs and tuples
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
pair
tuple(C++11)
piecewise_construct_t(C++11)
piecewise_construct(C++11)
フォワード、スワップ、および移動
Original:
Swap, forward and move
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
swap
forward(C++11)
move(C++11)
move_if_noexcept(C++11)
declval(C++11)
 
支援を入力します
基本的なタイプ
Original:
Basic types
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
基本的なタイプ
固定幅の整数型 (C++11)
数値の限界
Original:
Numeric limits
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
numeric_limits
Cの数値は、インターフェイスを制限します
実行時型情報
Original:
Runtime type information
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
型の特徴
Original:
Type traits
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
プライマリタイプカテゴリ
Original:
Primary type categories
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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プロパティ
Original:
Type properties
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
is_const(C++11)
is_volatile(C++11)
is_pod(C++11)
is_empty(C++11)
is_polymorphic(C++11)
is_abstract(C++11)
サポートされる操作
Original:
Supported operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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)
リレーションシップとプロパティクエリ
Original:
Relationships and property queries
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
is_same(C++11)
is_base_of(C++11)
is_convertible(C++11)
alignment_of(C++11)
rank(C++11)
extent(C++11)
型の変更
Original:
Type modifications
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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)
型変換
Original:
Type transformations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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)
形質定数を入力します
Original:
Type trait constants
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
integral_constant(C++11)
 
 
static const int digits10
(C + + 11時まで)
static constexpr int digits10
(C + + 11以来)
std::numeric_limits<T>::digits10の値は変更せずに型Tで表すことができ、10を底と桁数、つまり、あるいずれかに記載のアクセスこの多くの桁を持つ数値は丸めやオーバーフローのため変更することなく、型Tの値に、バック進数形式に変換することができます。ベースradixタイプの場合、それはdigitsdigits-1浮動小数点型の場合)を乗じた値であるlog
10
(radix)
でと切り捨て.
Original:
The value of std::numeric_limits<T>::digits10 is the number of base-10 digits that can be represented by the type T without change, that is, any number with this many decimal digits can be converted to a value of type T and back to decimal form, without change due to rounding or overflow. For base-radix types, it is the value of digits (digits-1 for floating-point types) multiplied by log
10
(radix)
and rounded down.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[編集] 標準の専門分野

T
std::numeric_limits<T>::digits10の値
Original:
value of std::numeric_limits<T>::digits10
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
/* non-specialized */ 0
bool 0
char std::numeric_limits<char>::digits * std::log10(2)
signed char std::numeric_limits<signed char>::digits * std::log10(2)
unsigned char std::numeric_limits<unsigned char>::digits * std::log10(2)
wchar_t std::numeric_limits<wchar_t>::digits * std::log10(2)
char16_t std::numeric_limits<char16_t>::digits * std::log10(2)
char32_t std::numeric_limits<char32_t>::digits * std::log10(2)
short std::numeric_limits<short>::digits * std::log10(2)
unsigned short std::numeric_limits<signed short>::digits * std::log10(2)
int std::numeric_limits<int>::digits * std::log10(2)
unsigned int std::numeric_limits<signed int>::digits * std::log10(2)
long std::numeric_limits<long>::digits * std::log10(2)
unsigned long std::numeric_limits<unsigned long>::digits * std::log10(2)
long long std::numeric_limits<long long>::digits * std::log10(2)
unsigned long long std::numeric_limits<unsigned long long>::digits * std::log10(2)
float FLT_DIG
double DBL_DIG
long double LDBL_DIG

[編集]

8ビットのバイナリ型は正確に、任意の2桁の10進数を表すことができますが、3桁の10進数256.. 999を表現できない。8ビット·タイプのdigits10の値です2(8 * std::log10(2)2.41である)
Original:
An 8-bit binary type can represent any two-digit decimal number exactly, but 3-digit decimal numbers 256..999 cannot be represented. The value of digits10 for an 8-bit type is 2 (8 * std::log10(2) is 2.41)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
標準の32ビットIEEE 754浮動小数点型は、それが7桁の小数を(24 * std::log10(2)7.22)を表すことができることを示唆している24ビットの小数部(23ビットが書かれた、暗黙の1)を有し、が、相対丸め誤差が不均一であると7桁でいくつかの浮動小数点値は、32ビット浮動小数点とバックへの変換は生き残れない:最小の正例は、往復の後8.589973e9なり8.589974e9、あるこれらの丸め誤差が超えることはできません。 1表現のビット、およびdigits10は6.92(24-1)*std::log10(2)、として計算されます。丸め値6の結果ダウン.
Original:
The standard 32-bit IEEE 754 floating-point type has a 24 bit fractional part (23 bits written, one implied), which may suggest that it can represent 7 digit decimals (24 * std::log10(2) is 7.22), but relative rounding errors are non-uniform and some floating-point values with 7 decimal digits do not survive conversion to 32-bit float and back: the smallest positive example is 8.589973e9, which becomes 8.589974e9 after the roundtrip. These rounding errors cannot exceed one bit in the representation, and digits10 is calculated as (24-1)*std::log10(2), which is 6.92. Rounding down results in the value 6.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[編集] も参照してください

[静的]
基数または指定されたタイプの表現で用いられる整数ベース
Original:
the radix or integer base used by the representation of the given type
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

(公共の静的メンバ定数) [edit]
[静的]
変更せずに表現することができるradixの桁数を指定します
Original:
number of radix digits that can be represented without change
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

(公共の静的メンバ定数) [edit]
有効な正規化された浮動小数点値である基数の最小の負のパワーよりも1
Original:
one more than the smallest negative power of the radix that is a valid normalized floating-point value
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

(公共の静的メンバ定数) [edit]
有効な有限浮動小数点値である基数の最大の整数乗よりも1
Original:
one more than the largest integer power of the radix that is a valid finite floating-point value
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

(公共の静的メンバ定数) [edit]