Struct core::fmt::Formatter1.0.0 [] [src]

pub struct Formatter<'a> { /* fields omitted */ }

A struct to represent both where to emit formatting strings to and how they should be formatted. A mutable version of this is passed to all formatting traits.

Methods

impl<'a> Formatter<'a>
[src]

Performs the correct padding for an integer which has already been emitted into a str. The str should not contain the sign for the integer, that will be added by this method.

Arguments

  • is_nonnegative - whether the original integer was either positive or zero.
  • prefix - if the '#' character (Alternate) is provided, thisis the prefix to put in front of the number.
  • buf - the byte array that the number has been formatted into

This function will correctly account for the flags provided as well as the minimum width. It will not take precision into account.

This function takes a string slice and emits it to the internal buffer after applying the relevant formatting flags specified. The flags recognized for generic strings are:

  • width - the minimum width of what to emit
  • fill/align - what to emit and where to emit it if the stringprovided needs to be padded
  • precision - the maximum length to emit, the string is truncated if itis longer than this length

Notably this function ignores the flag parameters.

Writes some data to the underlying buffer contained within this formatter.

Writes some formatted information into this instance

Flags for formatting (packed version of rt::Flag)

Character used as 'fill' whenever there is alignment

🔬 This is a nightly-only experimental API. (fmt_flags_align #27726)

method was just created

Flag indicating what form of alignment was requested

Optionally specified integer width that the output should be

Optionally specified precision for numeric types

Determines if the + flag was specified.

Determines if the - flag was specified.

Determines if the # flag was specified.

Determines if the 0 flag was specified.

Creates a DebugStruct builder designed to assist with creation of fmt::Debug implementations for structs.

Examples

use std::fmt;

struct Foo {
    bar: i32,
    baz: String,
}

impl fmt::Debug for Foo {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_struct("Foo")
            .field("bar", &self.bar)
            .field("baz", &self.baz)
            .finish()
    }
}

// prints "Foo { bar: 10, baz: "Hello World" }"
println!("{:?}", Foo { bar: 10, baz: "Hello World".to_string() });Run

Creates a DebugTuple builder designed to assist with creation of fmt::Debug implementations for tuple structs.

Examples

use std::fmt;

struct Foo(i32, String);

impl fmt::Debug for Foo {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_tuple("Foo")
            .field(&self.0)
            .field(&self.1)
            .finish()
    }
}

// prints "Foo(10, "Hello World")"
println!("{:?}", Foo(10, "Hello World".to_string()));Run

Creates a DebugList builder designed to assist with creation of fmt::Debug implementations for list-like structures.

Examples

use std::fmt;

struct Foo(Vec<i32>);

impl fmt::Debug for Foo {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_list().entries(self.0.iter()).finish()
    }
}

// prints "[10, 11]"
println!("{:?}", Foo(vec![10, 11]));Run

Creates a DebugSet builder designed to assist with creation of fmt::Debug implementations for set-like structures.

Examples

use std::fmt;

struct Foo(Vec<i32>);

impl fmt::Debug for Foo {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_set().entries(self.0.iter()).finish()
    }
}

// prints "{10, 11}"
println!("{:?}", Foo(vec![10, 11]));Run

Creates a DebugMap builder designed to assist with creation of fmt::Debug implementations for map-like structures.

Examples

use std::fmt;

struct Foo(Vec<(String, i32)>);

impl fmt::Debug for Foo {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_map().entries(self.0.iter().map(|&(ref k, ref v)| (k, v))).finish()
    }
}

// prints "{"A": 10, "B": 11}"
println!("{:?}", Foo(vec![("A".to_string(), 10), ("B".to_string(), 11)]));Run

Trait Implementations

impl<'a> Write for Formatter<'a>
1.2.0
[src]

Writes a slice of bytes into this writer, returning whether the write succeeded. Read more

Writes a [char] into this writer, returning whether the write succeeded. Read more

Glue for usage of the [write!] macro with implementors of this trait. Read more