}
}
- /// Optionally specified integer width that the output should be
+ /// Optionally specified integer width that the output should be.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::fmt;
+ ///
+ /// struct Foo(i32);
+ ///
+ /// impl fmt::Display for Foo {
+ /// fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ /// if let Some(width) = formatter.width() {
+ /// // If we received a width, we use it
+ /// write!(formatter, "{:width$}", &format!("Foo({})", self.0), width = width)
+ /// } else {
+ /// // Otherwise we do nothing special
+ /// write!(formatter, "Foo({})", self.0)
+ /// }
+ /// }
+ /// }
+ ///
+ /// assert_eq!(&format!("{:10}", Foo(23)), "Foo(23) ");
+ /// assert_eq!(&format!("{}", Foo(23)), "Foo(23)");
+ /// ```
#[stable(feature = "fmt_flags", since = "1.5.0")]
pub fn width(&self) -> Option<usize> { self.width }
- /// Optionally specified precision for numeric types
+ /// Optionally specified precision for numeric types.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::fmt;
+ ///
+ /// struct Foo(f32);
+ ///
+ /// impl fmt::Display for Foo {
+ /// fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ /// if let Some(precision) = formatter.precision() {
+ /// // If we received a precision, we use it.
+ /// write!(formatter, "Foo({1:.*})", precision, self.0)
+ /// } else {
+ /// // Otherwise we default to 2.
+ /// write!(formatter, "Foo({:.2})", self.0)
+ /// }
+ /// }
+ /// }
+ ///
+ /// assert_eq!(&format!("{:.4}", Foo(23.2)), "Foo(23.2000)");
+ /// assert_eq!(&format!("{}", Foo(23.2)), "Foo(23.20)");
+ /// ```
#[stable(feature = "fmt_flags", since = "1.5.0")]
pub fn precision(&self) -> Option<usize> { self.precision }
/// Determines if the `+` flag was specified.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::fmt;
+ ///
+ /// struct Foo(i32);
+ ///
+ /// impl fmt::Display for Foo {
+ /// fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ /// if formatter.sign_plus() {
+ /// write!(formatter,
+ /// "Foo({}{})",
+ /// if self.0 < 0 { '-' } else { '+' },
+ /// self.0)
+ /// } else {
+ /// write!(formatter, "Foo({})", self.0)
+ /// }
+ /// }
+ /// }
+ ///
+ /// assert_eq!(&format!("{:+}", Foo(23)), "Foo(+23)");
+ /// assert_eq!(&format!("{}", Foo(23)), "Foo(23)");
+ /// ```
#[stable(feature = "fmt_flags", since = "1.5.0")]
pub fn sign_plus(&self) -> bool { self.flags & (1 << FlagV1::SignPlus as u32) != 0 }
/// Determines if the `-` flag was specified.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::fmt;
+ ///
+ /// struct Foo(i32);
+ ///
+ /// impl fmt::Display for Foo {
+ /// fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ /// if formatter.sign_minus() {
+ /// // You want a minus sign? Have one!
+ /// write!(formatter, "-Foo({})", self.0)
+ /// } else {
+ /// write!(formatter, "Foo({})", self.0)
+ /// }
+ /// }
+ /// }
+ ///
+ /// assert_eq!(&format!("{:-}", Foo(23)), "-Foo(23)");
+ /// assert_eq!(&format!("{}", Foo(23)), "Foo(23)");
+ /// ```
#[stable(feature = "fmt_flags", since = "1.5.0")]
pub fn sign_minus(&self) -> bool { self.flags & (1 << FlagV1::SignMinus as u32) != 0 }
/// Determines if the `#` flag was specified.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::fmt;
+ ///
+ /// struct Foo(i32);
+ ///
+ /// impl fmt::Display for Foo {
+ /// fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ /// if formatter.alternate() {
+ /// write!(formatter, "Foo({})", self.0)
+ /// } else {
+ /// write!(formatter, "{}", self.0)
+ /// }
+ /// }
+ /// }
+ ///
+ /// assert_eq!(&format!("{:#}", Foo(23)), "Foo(23)");
+ /// assert_eq!(&format!("{}", Foo(23)), "23");
+ /// ```
#[stable(feature = "fmt_flags", since = "1.5.0")]
pub fn alternate(&self) -> bool { self.flags & (1 << FlagV1::Alternate as u32) != 0 }
/// Determines if the `0` flag was specified.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::fmt;
+ ///
+ /// struct Foo(i32);
+ ///
+ /// impl fmt::Display for Foo {
+ /// fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+ /// assert!(formatter.sign_aware_zero_pad());
+ /// assert_eq!(formatter.width(), Some(4));
+ /// // We ignore the formatter's options.
+ /// write!(formatter, "{}", self.0)
+ /// }
+ /// }
+ ///
+ /// assert_eq!(&format!("{:04}", Foo(23)), "23");
+ /// ```
#[stable(feature = "fmt_flags", since = "1.5.0")]
pub fn sign_aware_zero_pad(&self) -> bool {
self.flags & (1 << FlagV1::SignAwareZeroPad as u32) != 0