Namespace
Varianti

std::numeric_limits::digits10

Da cppreference.com.

Questa pagina è stata tradotta in modo automatico dalla versione in ineglese della wiki usando Google Translate.

La traduzione potrebbe contenere errori e termini strani. Muovi il puntatore sopra al testo per vedere la versione originale. Puoi aiutarci a correggere gli gli errori. Per ulteriori istruzioni clicca qui.

Click here for the English version of this page

 
C++
 
Utilità libreria
Tipo di supporto (basic types, RTTI, type traits)
Gestione della memoria dinamica
La gestione degli errori
Programma di utilità
Funzioni variadic
Data e ora
Funzione oggetti
initializer_list(C++11)
bitset
hash(C++11)
Gli operatori relazionali
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>=
Coppie e tuple
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)
Swap, in avanti e spostare
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)
 
Tipo di supporto
Tipi base
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.
Tipi fondamentali
Larghezza fissa interi tipi (C++11)
Limiti numerici
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 numerico limita interfaccia
Informazioni sul tipo di runtime
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.
Tipo tratti
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.
Categorie di tipo primario
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)
Proprietà del tipo
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)
Operazioni supportate
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)
I rapporti e le query di proprietà
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)
Tipo modifiche
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)
Tipo di trasformazioni
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)
Digitare costanti tratto
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)
 
std::numeric_limits
Costanti statiche
Original:
Static constants
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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
Funzioni membro statiche
Original:
Static member functions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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 tipi
Original:
Helper types
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
float_round_style
float_denorm_style
 
static const int digits10
 (fino al c++11)
static constexpr int digits10
 (dal C++11)
Il valore std::numeric_limits<T>::digits10 è il numero di base 10 cifre che può essere rappresentato dal tipo T senza cambiamento, cioè, qualsiasi con questo numero di molte cifre decimali può essere convertito in un valore di tipo T e ritorno alla forma decimale, senza modifiche a causa degli arrotondamenti o troppo pieno. Per base-radix tipi, è il valore di digits (digits-1 per tipi a virgola mobile) moltiplicato da log
10(radix) e arrotondato verso il basso.
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.

[modifica] Specializzazioni standard

T
valore di std::numeric_limits<T>::digits10
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

[modifica] Esempio

a 8 bit tipo binario può rappresentare qualsiasi numero di due cifre decimali esattamente, ma i numeri a 3 cifre decimali 256.. 999 non può essere rappresentato. Il valore di digits10 per un 8 bit tipo è 2 (8 * std::log10(2) è 2.41)
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.
Lo standard a 32 bit IEEE 754 in virgola mobile di tipo ha una parte frazionaria a 24 bit (23 bit scritto, una implicita), che può suggerire che può rappresentare sette cifre decimali (24 * std::log10(2) è 7.22) , ma gli errori di arrotondamento relativi non sono uniformi e alcuni valori a virgola mobile con 7 cifre decimali non sopravvivono conversione a 32-bit a virgola mobile e viceversa: il più piccolo esempio positivo è 8.589973e9, che diventa 8.589974e9 dopo l'andata e ritorno Questi errori di arrotondamento non può superare. un bit nella rappresentazione, e digits10 è calcolato come (24-1)*std::log10(2), che è 6.92. arrotondamento verso il basso risulta il valore 6.
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.

[modifica] Vedi anche

[statico]
la radice o base intero utilizzato dalla rappresentazione del tipo specificato
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.

(pubblico membro statico costante) [modifica]
[statico]
numero di cifre radix che possono essere rappresentati senza cambiamenti
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.

(pubblico membro statico costante) [modifica]
[statico]
oltre la più piccola potenza negativa della radice che è una valida virgola mobile normalizzato valore uno
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.

(pubblico membro statico costante) [modifica]
[statico]
maggiore della massima potenza intera della radice che è una valida finita valore a virgola mobile uno
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.

(pubblico membro statico costante) [modifica]
Estratto da "https://it.cppreference.com/mwiki/index.php?title=cpp/types/numeric_limits/digits10&oldid=27064"