why these not const

src/integer.rs

@@ -10,24 +10,24 @@ impl Time{
 	pub const ONE_MICROSECOND:Self=Self(1_000);
 	pub const ONE_NANOSECOND:Self=Self(1);
 	#[inline]
-	pub fn from_secs(num:i64)->Self{
+	pub const fn from_secs(num:i64)->Self{
 		Self(Self::ONE_SECOND.0*num)
 	}
 	#[inline]
-	pub fn from_millis(num:i64)->Self{
+	pub const fn from_millis(num:i64)->Self{
 		Self(Self::ONE_MILLISECOND.0*num)
 	}
 	#[inline]
-	pub fn from_micros(num:i64)->Self{
+	pub const fn from_micros(num:i64)->Self{
 		Self(Self::ONE_MICROSECOND.0*num)
 	}
 	#[inline]
-	pub fn from_nanos(num:i64)->Self{
+	pub const fn from_nanos(num:i64)->Self{
 		Self(Self::ONE_NANOSECOND.0*num)
 	}
 	//should I have checked subtraction? force all time variables to be positive?
 	#[inline]
-	pub fn nanos(&self)->i64{
+	pub const fn nanos(self)->i64{
 		self.0
 	}
 }