xtd - Reference Guide  0.2.0 Modern c++17/20 framework to create console, GUI and unit test applications on Windows, macOS, Linux, iOS and android.
format and parse

## Definition

All needed for formating or parsing object.

Remarks

## Functions

template<>
drawing::color xtd::parse< drawing::color > (const std::string &str)
Creates a xtd::drawing::color class from the specified name. More...

## Methods

template<typename ... args_t>
static ustring xtd::ustring::format (const ustring &fmt, args_t &&... args)
Writes the text representation of the specified arguments list, to string using the specified format information. More...

template<typename ... args_t>
static ustring xtd::ustring::sprintf (const ustring &fmt, args_t &&... args) noexcept
Writes the text representation of the specified arguments list, to string using the specified format information. More...

## ◆ format()

template<typename ... args_t>
 static ustring xtd::ustring::format ( const ustring & fmt, args_t &&... args )
inlinestatic

#include <xtd.core/include/xtd/ustring.h>

Writes the text representation of the specified arguments list, to string using the specified format information.

Parameters
 fmt A composite format string. args arguments list to write using format.
Returns
string formatted.
Remarks
Examples:

## ◆ parse< drawing::color >()

template<>
 drawing::color xtd::parse< drawing::color > ( const std::string & str )
inline

#include <xtd.drawing/include/xtd/drawing/color.h>

Creates a xtd::drawing::color class from the specified name.

Parameters
 name A string that is the name of a predefined color. Valid names are the same as the names of the elements of the xtd::drawing::known_color enumeration or hexadecimal value that represents argb value, or four decimal values separated by a comma representing respectively a, r, g, b, values.
Returns
xtd::drawing::color The xtd::drawing::color structure that this method creates.

## ◆ sprintf()

template<typename ... args_t>
 static ustring xtd::ustring::sprintf ( const ustring & fmt, args_t &&... args )
inlinestaticnoexcept

#include <xtd.core/include/xtd/ustring.h>

Writes the text representation of the specified arguments list, to string using the specified format information.

Parameters
 fmt A composite format string. args arguments list to write using format.
Returns
string formatted.
Remarks
A format specifier follows this prototype:
%[flags][width][.precision][length]specifier
specifier Output Example
d or i Signed decimal integer 392
u Unsigned decimal integer 7235
o Unsigned octal 610
X Unsigned hexadecimal integer (uppercase) 7FA
f Decimal floating point, lowercase 392.65
F Decimal floating point, lowercase (uppercase) 392.65
e Scientific notation (mantissa/exponent), lowercase 3.9265e+2
E Scientific notation (mantissa/exponent), uppercase 3.9265E+2
g Use the shortest representation: e or f 392.65
G Use the shortest representation: E or F 392.65
a Hexadecimal floating point, lowercase -0xc.90fep-2
A Hexadecimal floating point, uppercase -0XC.90FEP-2
c Character a
s string of characters sample
n Nothing printed. The corresponding argument must be a pointer to a signed int. The number of characters written so far is stored in the pointed location
% A % followed by another % character will write a single % to the stream. %
The format specifier can also contain sub-specifiers: flags, width, .precision and modifiers (in that order), which are optional and follow these specifications:
flags description
- Left-justify within the given field width; Right justification is the default (see width sub-specifier).
+ Forces to prefix the result with a plus or minus sign (+ or -) even for positive numbers. By default, only negative numbers are preceded with a - sign.
(space) If no sign is going to be written, a blank space is inserted before the value.
# Used with o, x or X specifiers the value is prefixed with 0, 0x or 0X respectively for values different than zero. Used with a, A, e, E, f, F, g or G it forces the written output to contain a decimal point even if no more digits follow. By default, if no digits follow, no decimal point is written.
0 Left-pads the number with zeroes (0) instead of spaces when padding is specified (see width sub-specifier).
width description
(number) Minimum number of characters to be printed. If the value to be printed is shorter than this number, the result is padded with blank spaces. The value is not truncated even if the result is larger.
* The width is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted.
.precision description
.number For integer specifiers (d, i, o, u, x, X): precision specifies the minimum number of digits to be written. If the value to be written is shorter than this number, the result is padded with leading zeros. The value is not truncated even if the result is longer. A precision of 0 means that no character is written for the value 0. For a, A, e, E, f and F specifiers: this is the number of digits to be printed after the decimal point (by default, this is 6). For g and G specifiers: This is the maximum number of significant digits to be printed. For s: this is the maximum number of characters to be printed. By default all characters are printed until the ending null character is encountered. If the period is specified without an explicit value for precision, 0 is assumed.
.* The precision is not specified in the format string, but as an additional integer value argument preceding the argument that has to be formatted.
The length sub-specifier modifies the length of the data type. This is a chart showing the types used to interpret the corresponding arguments with and without length specifier (if a different type is used, the proper type promotion or conversion is performed, if allowed):
length d i u o x X f F e E g G a A c s p n
(none) int unsigned int double int char8_t* void* int*
hh signed char8_t unsigned char8_t unsigned char8_t*
h short int unsigned short int short int*
l long int unsigned long int win_t wchar_t* long int*
ll long long int unsigned long long int long long int*
j intmax_t uintmax_t intmax_t*
z size_t size_t size_t*
t ptrdiff_t ptrdiff_t ptrdiff_t*
L long double
Note regarding the c specifier: it takes an int (or wint_t) as argument, but performs the proper conversion to a char8_t value (or a wchar_t) before formatting it for output.
you can use std::string or std::wstring with format param %s.