Constify functions that can be constified.

src/ansi.rs

@@ -194,7 +194,7 @@ impl Style {
     /// assert_eq!("",
     ///            style.prefix().to_string());
     /// ```
-    pub fn prefix(self) -> Prefix {
+    pub const fn prefix(self) -> Prefix {
         Prefix(self)
     }
 
@@ -219,7 +219,7 @@ impl Style {
     /// assert_eq!("",
     ///            style.infix(style).to_string());
     /// ```
-    pub fn infix(self, next: Style) -> Infix {
+    pub const fn infix(self, next: Style) -> Infix {
         Infix(self, next)
     }
 
@@ -243,7 +243,7 @@ impl Style {
     /// assert_eq!("",
     ///            style.suffix().to_string());
     /// ```
-    pub fn suffix(self) -> Suffix {
+    pub const fn suffix(self) -> Suffix {
         Suffix(self)
     }
 }

src/display.rs

@@ -107,7 +107,7 @@ where
     <S as ToOwned>::Owned: fmt::Debug,
 {
     /// Directly access the style
-    pub fn style_ref(&self) -> &Style {
+    pub const fn style_ref(&self) -> &Style {
         &self.style
     }
 
@@ -136,7 +136,7 @@ pub type AnsiStrings<'a> = AnsiGenericStrings<'a, str>;
 
 /// A function to construct an `AnsiStrings` instance.
 #[allow(non_snake_case)]
-pub fn AnsiStrings<'a>(arg: &'a [AnsiString<'a>]) -> AnsiStrings<'a> {
+pub const fn AnsiStrings<'a>(arg: &'a [AnsiString<'a>]) -> AnsiStrings<'a> {
     AnsiGenericStrings(arg)
 }
 
@@ -146,7 +146,7 @@ pub type AnsiByteStrings<'a> = AnsiGenericStrings<'a, [u8]>;
 
 /// A function to construct an `AnsiByteStrings` instance.
 #[allow(non_snake_case)]
-pub fn AnsiByteStrings<'a>(arg: &'a [AnsiByteString<'a>]) -> AnsiByteStrings<'a> {
+pub const fn AnsiByteStrings<'a>(arg: &'a [AnsiByteString<'a>]) -> AnsiByteStrings<'a> {
     AnsiGenericStrings(arg)
 }
 

src/gradient.rs

@@ -16,6 +16,7 @@ impl Gradient {
     pub const fn new(start: Rgb, end: Rgb) -> Self {
         Self { start, end }
     }
+
     pub const fn from_color_rgb(start: Color, end: Color) -> Self {
         let start_grad = match start {
             Color::Rgb(r, g, b) => Rgb { r, g, b },

src/rgb.rs

@@ -122,15 +122,15 @@ impl ANSIColorCode for Rgb {
     }
 }
 
-fn rgb_add(lhs: &Rgb, rhs: &Rgb) -> Rgb {
+const fn rgb_add(lhs: &Rgb, rhs: &Rgb) -> Rgb {
     Rgb::new(
         lhs.r.saturating_add(rhs.r),
         lhs.g.saturating_add(rhs.g),
         lhs.b.saturating_add(rhs.b),
     )
 }
 
-fn rgb_sub(lhs: &Rgb, rhs: &Rgb) -> Rgb {
+const fn rgb_sub(lhs: &Rgb, rhs: &Rgb) -> Rgb {
     Rgb::new(
         lhs.r.saturating_sub(rhs.r),
         lhs.g.saturating_sub(rhs.g),
@@ -146,7 +146,7 @@ fn rgb_mul_f32(lhs: &Rgb, rhs: &f32) -> Rgb {
     )
 }
 
-fn rgb_negate(rgb: &Rgb) -> Rgb {
+const fn rgb_negate(rgb: &Rgb) -> Rgb {
     Rgb::new(255 - rgb.r, 255 - rgb.g, 255 - rgb.b)
 }
 

src/style.rs

@@ -71,7 +71,7 @@ impl Style {
     /// let style = Style::new().bold();
     /// println!("{}", style.paint("hey"));
     /// ```
-    pub fn bold(&self) -> Style {
+    pub const fn bold(&self) -> Style {
         Style {
             is_bold: true,
             ..*self
@@ -88,7 +88,7 @@ impl Style {
     /// let style = Style::new().dimmed();
     /// println!("{}", style.paint("sup"));
     /// ```
-    pub fn dimmed(&self) -> Style {
+    pub const fn dimmed(&self) -> Style {
         Style {
             is_dimmed: true,
             ..*self
@@ -105,7 +105,7 @@ impl Style {
     /// let style = Style::new().italic();
     /// println!("{}", style.paint("greetings"));
     /// ```
-    pub fn italic(&self) -> Style {
+    pub const fn italic(&self) -> Style {
         Style {
             is_italic: true,
             ..*self
@@ -122,7 +122,7 @@ impl Style {
     /// let style = Style::new().underline();
     /// println!("{}", style.paint("salutations"));
     /// ```
-    pub fn underline(&self) -> Style {
+    pub const fn underline(&self) -> Style {
         Style {
             is_underline: true,
             ..*self
@@ -138,7 +138,7 @@ impl Style {
     /// let style = Style::new().blink();
     /// println!("{}", style.paint("wazzup"));
     /// ```
-    pub fn blink(&self) -> Style {
+    pub const fn blink(&self) -> Style {
         Style {
             is_blink: true,
             ..*self
@@ -155,7 +155,7 @@ impl Style {
     /// let style = Style::new().reverse();
     /// println!("{}", style.paint("aloha"));
     /// ```
-    pub fn reverse(&self) -> Style {
+    pub const fn reverse(&self) -> Style {
         Style {
             is_reverse: true,
             ..*self
@@ -172,7 +172,7 @@ impl Style {
     /// let style = Style::new().hidden();
     /// println!("{}", style.paint("ahoy"));
     /// ```
-    pub fn hidden(&self) -> Style {
+    pub const fn hidden(&self) -> Style {
         Style {
             is_hidden: true,
             ..*self
@@ -189,7 +189,7 @@ impl Style {
     /// let style = Style::new().strikethrough();
     /// println!("{}", style.paint("yo"));
     /// ```
-    pub fn strikethrough(&self) -> Style {
+    pub const fn strikethrough(&self) -> Style {
         Style {
             is_strikethrough: true,
             ..*self
@@ -206,7 +206,7 @@ impl Style {
     /// let style = Style::new().fg(Color::Yellow);
     /// println!("{}", style.paint("hi"));
     /// ```
-    pub fn fg(&self, foreground: Color) -> Style {
+    pub const fn fg(&self, foreground: Color) -> Style {
         Style {
             foreground: Some(foreground),
             ..*self
@@ -223,7 +223,7 @@ impl Style {
     /// let style = Style::new().on(Color::Blue);
     /// println!("{}", style.paint("eyyyy"));
     /// ```
-    pub fn on(&self, background: Color) -> Style {
+    pub const fn on(&self, background: Color) -> Style {
         Style {
             background: Some(background),
             ..*self