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Struct `std.format.FormatSpec`

A General handler for printf style format specifiers. Used for building more specific formatting functions.



struct FormatSpec(Char)


  


if (is(Unqual!Char == Char));

Constructors

Name	Description
`this` (fmt)	Construct a new `FormatSpec` using the format string `fmt`, no processing is done until needed.

Fields

Name	Type	Description
`flDash`	`bool`	The format specifier contained a `'-'` (`printf` compatibility).
`flHash`	`bool`	The format specifier contained a `'#'` (`printf` compatibility).
`flPlus`	`bool`	The format specifier contained a `'+'` (`printf` compatibility).
`flSeparator`	`bool`	The format specifier contained a `','`
`flSpace`	`bool`	The format specifier contained a `' '` (`printf` compatibility).
`flZero`	`bool`	The format specifier contained a `'0'` (`printf` compatibility).
`indexEnd`	`ubyte`	Index of the last argument for positional parameter range, from `1` to `ubyte.max`. (`0` means not used).
`indexStart`	`ubyte`	Index of the argument for positional parameters, from `1` to `ubyte.max`. (`0` means not used).
`nested`	`const(Char)[]`	In case of a compound format specifier starting with `"%("` and ending with `"%)"`, `_nested` contains the string contained within the two separators.
`precision`	`int`	Precision. Its semantics depends on the argument type. For floating point numbers, precision dictates the number of decimals printed.
`sep`	`const(Char)[]`	In case of a compound format specifier, `_sep` contains the string positioning after `"%\|"`. `sep is null` means no separator else `sep.empty` means 0 length separator.
`separatorChar`	`dchar`	Character to insert between digits.
`separatorCharPos`	`int`	Set to `DYNAMIC` when the separator character is supplied at runtime.
`separators`	`int`	Number of digits printed between separators.
`spec`	`char`	The actual format specifier, `'s'` by default.
`trailing`	`const(Char)[]`	`_trailing` contains the rest of the format string.
`width`	`int`	Minimum width, default `0`.

Methods

Name	Description
`toString` (writer)	Gives a string containing all of the member variables on their own line.
`writeUpToNextSpec` (writer)	Write the format string to an output range until the next format specifier is found and parse that format specifier.

Example

import std.array;
auto a = appender!(string)();
auto fmt = "Number: %6.4e\nString: %s";
auto f = FormatSpec!char(fmt);

writeln(f.writeUpToNextSpec(a)); // true

writeln(a.data); // "Number: "
writeln(f.trailing); // "\nString: %s"
writeln(f.spec); // 'e'
writeln(f.width); // 6
writeln(f.precision); // 4

writeln(f.writeUpToNextSpec(a)); // true

writeln(a.data); // "Number: \nString: "
writeln(f.trailing); // ""
writeln(f.spec); // 's'

writeln(f.writeUpToNextSpec(a)); // false
writeln(a.data); // "Number: \nString: "

Authors

Walter Bright, Andrei Alexandrescu, and Kenji Hara

License

Boost License 1.0.