diff --git a/src/strings/capped.rs b/src/strings/capped.rs
index 84b8080..7104df6 100644
--- a/src/strings/capped.rs
+++ b/src/strings/capped.rs
@@ -20,12 +20,24 @@ use alloc::{
 #[cfg(feature = "std")]
 use std::borrow::Cow;
 
+#[derive(Debug)]
+pub struct CapacityError;
+
+impl fmt::Display for CapacityError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "`CappedString` capacity exceeded")
+    }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for CapacityError {}
+
 /// A string type which stores at most `N` bytes of string data. The string data is stored inline
 /// rather than using a heap allocation.
 ///
 /// ```
 /// # use libshire::strings::CappedString;
-/// # fn main() -> Result<(), libshire::strings::capped::Error> {
+/// # fn main() -> Result<(), libshire::strings::capped::CapacityError> {
 /// let s = CappedString::<16>::new("hello world")?;
 /// assert_eq!(&*s, "hello world");
 /// # Ok(())
@@ -50,8 +62,8 @@ impl<const N: usize> CappedString<N> {
     /// Creates a new `CappedString` from a given byte buffer and length.
     ///
     /// # Safety
-    ///
-    /// The first `len` bytes of `buf` (i.e. `buf[..len]`) must be initialised and valid UTF-8.
+    /// The first `len` bytes of `buf` (i.e. `buf[..len]`) must be initialised and valid UTF-8. 
+    /// `len` must be less than or equal to `N`.
     #[inline]
     #[must_use]
     pub const unsafe fn from_raw_parts(buf: [MaybeUninit<u8>; N], len: u8) -> Self {
@@ -60,10 +72,76 @@ impl<const N: usize> CappedString<N> {
 
     #[inline]
     #[must_use]
-    pub fn into_raw_parts(self) -> ([MaybeUninit<u8>; N], u8) {
+    pub const fn into_raw_parts(self) -> ([MaybeUninit<u8>; N], u8) {
         (self.buf, self.len)
     }
 
+    /// # Safety
+    /// `src` must point to `len` bytes of valid, UTF-8 string data. `len` must be less than or
+    /// equal to `N`.
+    #[inline]
+    unsafe fn from_raw_ptr(src: *const u8, len: u8) -> Self {
+        // `u8` has the same memory layout as `MaybeUninit<u8>`, so this cast is valid.
+        let src = src as *const MaybeUninit<u8>;
+
+        // SAFETY:
+        // `MaybeUninit::uninit()` is a valid value for `[MaybeUninit<u8>; N]`, since each element
+        // of the array is allowed to be uninitialised.
+        let mut buf = unsafe { MaybeUninit::<[MaybeUninit<u8>; N]>::uninit().assume_init() };
+
+        // SAFETY:
+        // The caller is responsible for ensuring that `src` points to a valid string, which means
+        // that it must not overlap with the new local variable `buf`. The caller is responsible
+        // for ensuring that `src` is valid for reads of `len` bytes. The caller is responsible for
+        // ensuring that `len <= N`, so `buf` is valid for writes of `len` bytes. `src` and `buf`
+        // are both trivially properly aligned, since they both have an alignment of 1.
+        unsafe { ptr::copy_nonoverlapping(src, buf.as_mut_ptr(), usize::from(len)); }
+
+        // SAFETY:
+        // The caller is responsible for ensuring that `src` points to `len` bytes of valid UTF-8
+        // data. `src` is copied into the start of `buf`, so the first `len` bytes of `buf` are
+        // valid UTF-8. The caller is responsible for ensuring that `len <= N`.
+        unsafe { Self::from_raw_parts(buf, len) }
+    }
+
+    /// # Safety
+    /// `self.len` must be less than `N`, so that there is space in the buffer to append the byte.
+    /// The byte must be a valid UTF-8 codepoint; it must be in the range `0..=127`.
+    #[inline]
+    unsafe fn append_byte(&mut self, byte: u8) {
+        // SAFETY:
+        // The caller is responsible for ensuring that `self.len < N`.
+        let dst = unsafe { self.buf.get_unchecked_mut(usize::from(self.len)) };
+        
+        *dst = MaybeUninit::new(byte);
+        self.len += 1;
+    }
+
+    /// # Safety
+    /// `src` must point to `len` bytes of valid UTF-8 string data. `len` must be less than or equal
+    /// to `N - self.len`.
+    #[inline]
+    unsafe fn append_bytes(&mut self, src: *const u8, len: u8) {
+        // `u8` has the same memory layout as `MaybeUninit<u8>`, so this cast is valid.
+        let src = src as *const MaybeUninit<u8>;
+
+        // SAFETY:
+        // `self.len <= N` is an invariant of `CappedString`, so `self.len..` is a valid range over
+        // `self.buf`.
+        let dst = unsafe { self.buf.get_unchecked_mut(usize::from(self.len)..) };
+
+        // SAFETY:
+        // The caller is responsible for ensuring that `src` points to a valid string, which means
+        // that it cannot overlap with the new local variable `buf`. The caller is responsible for
+        // ensuring that `src` is valid for reads of `len` bytes. The caller is responsible for
+        // ensuring that `len <= N - self.len`, so the destination `dst = self.buf[self.len..]` is
+        // valid for writes of `len` bytes. `src` and `dst` are both trivially properly aligned,
+        // since they both have an alignment of 1.
+        unsafe { ptr::copy_nonoverlapping(src, dst.as_mut_ptr(), usize::from(len)); }
+
+        self.len += len;
+    }
+
     /// Returns a new empty `CappedString`.
     ///
     /// ```
@@ -90,53 +168,224 @@ impl<const N: usize> CappedString<N> {
     /// Returns a new `CappedString` containing the given string data. The string data will be
     /// stored inline; no heap allocation is used. An error will be returned if the length of the
     /// provided string exceeds the `CappedString`'s maximum length, `N`.
+    /// 
+    /// If you would like a version which never returns an error, see [`Self::new_truncating`].
     ///
     /// ```
     /// # use libshire::strings::CappedString;
-    /// # fn main() -> Result<(), libshire::strings::capped::Error> {
+    /// # fn main() -> Result<(), libshire::strings::capped::CapacityError> {
     /// let s = CappedString::<16>::new("hello world")?;
     /// assert_eq!(&*s, "hello world");
     /// # Ok(())
     /// # }
     /// ```
     #[inline]
-    pub fn new<S>(s: &S) -> Result<Self, Error>
+    pub fn new<S>(src: &S) -> Result<Self, CapacityError>
     where
         S: AsRef<str> + ?Sized,
     {
         // Convert the string to a byte slice, which is guaranteed to be valid UTF-8 since this is
         // an invariant of `str`.
-        let src = <S as AsRef<str>>::as_ref(s).as_bytes();
-
-        // If the length of the string is greater than `Self::MAX_LEN`, it will not fit in the
-        // buffer so return `None`.
-        let len = u8::try_from(src.len())
-            .ok()
-            .and_then(|len| (len <= Self::MAX_LEN).then_some(len))
-            .ok_or(Error {
-                max_len: N,
-                actual_len: src.len(),
-            })?;
+        let src = <S as AsRef<str>>::as_ref(src);
+
+        // If the length of the `src` string does not fit into a `u8` or is greater than 
+        // `Self::MAX_LEN`, we can't fit it into the new `CappedString` so return an error.
+        let len = match u8::try_from(src.len()) {
+            Ok(len) if len <= Self::MAX_LEN => len,
+            _ => return Err(CapacityError),
+        };
 
         // SAFETY:
-        // `MaybeUninit::uninit()` is a valid value for `[MaybeUninit<u8>; N]`, since each element
-        // of the array is allowed to be uninitialised.
-        let mut buf = unsafe { MaybeUninit::<[MaybeUninit<u8>; N]>::uninit().assume_init() };
+        // `src.as_ptr()` points to `len` bytes of valid UTF-8 string data since `src` is a `&str`
+        // and `len` is its length. `len` is less than or equal to `Self::MAX_LEN`, which is equal
+        // to `N`.
+        unsafe { Ok(Self::from_raw_ptr(src.as_ptr(), len)) }
+    }
+
+    /// Returns a new `CappedString` containing the given string data. The string data will be
+    /// stored inline; no heap allocation is used. If the length of the provided string exceeds the
+    /// `CappedString`'s maximum length, `N`, it will be truncated to fit.
+    /// 
+    /// If you would like a version which returns an error rather than truncating the string, see
+    /// [`Self::new`].
+    /// 
+    /// ```
+    /// # use libshire::strings::CappedString;
+    /// let s1 = CappedString::<15>::new_truncating("こんにちは");
+    /// assert_eq!(&*s1, "こんにちは");
+    /// 
+    /// let s2 = CappedString::<10>::new_truncating("こんにちは");
+    /// assert_eq!(&*s2, "こんに");
+    /// ```
+    #[inline]
+    #[must_use]
+    pub fn new_truncating<S>(src: &S) -> Self
+    where
+        S: AsRef<str> + ?Sized,
+    {
+        let src = <S as AsRef<str>>::as_ref(src);
 
-        let src_ptr = src.as_ptr() as *const MaybeUninit<u8>;
+        let (src, len) = truncate_str(src, Self::MAX_LEN);
 
         // SAFETY:
-        // The source and destination to not overlap, since `buf` is a new local variable which is
-        // completely separate from the provided source string `s`. The source is valid for reads of
-        // `len` bytes since `len == src.len()`, and the destination is valid for writes of `len`
-        // bytes since `len <= N`. The source and destination are both trivially properly aligned,
-        // since they both have an alignment of 1.
-        unsafe { ptr::copy_nonoverlapping(src_ptr, buf.as_mut_ptr(), usize::from(len)) }
+        // It is part of the contract of `truncate_str` that it returns a pointer to a valid UTF-8
+        // string of length `len`, and that `len` is less than or equal to the provided maximum
+        // length, which is `Self::MAX_LEN` (which is equal to `N`) in this case.
+        unsafe { Self::from_raw_ptr(src, len) }
+    }
+
+    /// Appends the given character to the end of this `CappedString`, returning an error if there
+    /// is insufficient capacity remaining to do so.
+    /// 
+    /// If you do not care whether or not the append succeeds, see [`Self::push_truncating`].
+    #[inline]
+    pub fn push(&mut self, c: char) -> Result<(), CapacityError> {
+        let mut char_buf = [0u8; 4];
+        let encoded = c.encode_utf8(&mut char_buf);
+
+        match encoded.len() {
+            1 => {
+                if self.len == Self::MAX_LEN {
+                    return Err(CapacityError);
+                }
+
+                // SAFETY:
+                // We have checked that `self.len != N` (`Self::MAX_LEN == N`). Since it is an
+                // invariant of `CappedString` that `self.len <= N`, it must hold that 
+                // `self.len < N`. The first byte of a `str` of length 1 must be a valid UTF-8
+                // codepoint; it must be in the range `0..=127`, since anything outside this range
+                // implies the presence of further bytes.
+                unsafe { self.append_byte(encoded.as_bytes()[0]) }
+
+                Ok(())
+            },
+
+            _ => self.push_str(encoded),
+        }
+    }
+
+    /// Appends the given character to the end of this `CappedString`, failing silently if there is
+    /// insufficient capacity remaining to do so.
+    /// 
+    /// If you would like to know whether or not the append succeeds, see [`Self::push`].
+    #[inline]
+    pub fn push_truncating(&mut self, c: char) {
+        // Unlike `Self::push_str_truncating`, we can just use `Self::push` and swallow the error
+        // because a single character will never be partially pushed; it is either pushed or it
+        // isn't.
+        self.push(c).ok();
+    }
+
+    /// Appends the given string slice to the end of this `CappedString`, returning an error if
+    /// there is insufficient capacity remaining to do so.
+    /// 
+    /// If you would like a version which cannot fail, see [`Self::push_str_truncating`].
+    /// 
+    /// ```
+    /// # use libshire::strings::CappedString;
+    /// let mut s = CappedString::<8>::empty();
+    /// 
+    /// assert!(s.push_str("hello").is_ok());
+    /// assert_eq!(&*s, "hello");
+    /// 
+    /// assert!(s.push_str(" world").is_err());
+    /// assert_eq!(&*s, "hello");
+    /// 
+    /// assert!(s.push_str("!!!").is_ok());
+    /// assert_eq!(&*s, "hello!!!");
+    /// ```
+    #[inline]
+    pub fn push_str<S>(&mut self, src: &S) -> Result<(), CapacityError>
+    where
+        S: AsRef<str> + ?Sized,
+    {
+        let src = <S as AsRef<str>>::as_ref(src);
+
+        let len = match u8::try_from(src.len()) {
+            Ok(len) if len <= Self::MAX_LEN - self.len => len,
+            _ => return Err(CapacityError),
+        };
+
+        // SAFETY:
+        // `src` is a valid string slice with length `len`. We have checked that
+        // `len <= N - self.len` holds above (note that `Self::MAX_LEN == N`).
+        unsafe { self.append_bytes(src.as_ptr(), len); }
+
+        Ok(())
+    }
+
+    /// Appends as many of the characters of the given string slice to the end of this 
+    /// `CappedString` as can fit. Any remaining characters will not be added.
+    /// 
+    /// If you would like a version which returns an error if there is not enough capacity remaining
+    /// to append the entire string slice, see [`Self::push_str`].
+    /// 
+    /// ```
+    /// # use libshire::strings::CappedString;
+    /// let mut s = CappedString::<10>::empty();
+    /// 
+    /// s.push_str_truncating("hello");
+    /// assert_eq!(&*s, "hello");
+    /// 
+    /// s.push_str_truncating(" 世界");
+    /// assert_eq!(&*s, "hello 世");
+    /// 
+    /// s.push_str_truncating("!!!");
+    /// assert_eq!(&*s, "hello 世!");
+    /// ```
+    #[inline]
+    pub fn push_str_truncating<S>(&mut self, src: &S)
+    where
+        S: AsRef<str> + ?Sized,
+    {
+        let remaining_cap = Self::MAX_LEN - self.len;
+
+        // Short-circuit if we have no space left to copy into.
+        if remaining_cap == 0 {
+            return;
+        }
+
+        let src = <S as AsRef<str>>::as_ref(src);
+
+        // Find the longest valid UTF-8 prefix which fits into the remaining space.
+        let (src, len) = truncate_str(src, remaining_cap);
 
         // SAFETY:
-        // The first `len` bytes of the buffer are valid UTF-8 because the first `len` bytes of
-        // the buffer contain data copied from a `&str`, and `&str` is always valid UTF-8.
-        unsafe { Ok(Self::from_raw_parts(buf, len)) }
+        // `truncate_str` returns a pointer to `len` bytes of valid UTF-8 string data. The returned
+        // `len` will always be less than or equal to `remaining_cap`, which is equal to
+        // `N - self.len` (note that `Self::MAX_LEN == N`).
+        unsafe { self.append_bytes(src, len); }
+    }
+
+    /// Empties the contents of this `CappedString`.
+    /// 
+    /// ```
+    /// # use libshire::strings::CappedString;
+    /// # fn main() -> Result<(), libshire::strings::capped::CapacityError> {
+    /// let mut s = CappedString::<16>::new("hello")?;
+    /// 
+    /// assert!(!s.is_empty());
+    /// assert_eq!(&*s, "hello");
+    /// 
+    /// s.clear();
+    /// 
+    /// assert!(s.is_empty());
+    /// assert_eq!(&*s, "");
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn clear(&mut self) {
+        // Setting the length to 0 is enough to clear the `CappedString`; we don't need to replace
+        // any of the old bytes in the buffer, as setting the length to 0 makes all of the old bytes
+        // inaccessible via safe methods, and means that any future calls to `Self::push` and
+        // friends will write over the old bytes.
+        // 
+        // It may be desirable for security-critical code to zero the old buffer to prevent cleared
+        // data from being exposed via buffer-overflow exploits or similar. However, this should be
+        // implemented in a separate function so that regular users don't have to pay the cost of
+        // zeroing the buffer.
+        self.len = 0;
     }
 
     /// Returns a string slice pointing to the underlying string data.
@@ -150,15 +399,37 @@ impl<const N: usize> CappedString<N> {
     }
 
     /// Returns a mutable string slice pointing to the underlying string data.
+    /// 
+    /// ```
+    /// # use libshire::strings::CappedString;
+    /// # fn main() -> Result<(), libshire::strings::capped::CapacityError> {
+    /// let mut s = CappedString::<16>::new("hello!")?;
+    /// s.as_str_mut().make_ascii_uppercase();
+    /// assert_eq!(&*s, "HELLO!");
+    /// # Ok(())
+    /// # }
+    /// ```
     #[inline]
     #[must_use]
     pub fn as_str_mut(&mut self) -> &mut str {
         // SAFETY:
         // The first `self.len` bytes of `self.buf` (which is returned by `Self::as_bytes_mut`)
-        // being valid UTF-8 is an invariant of `CappedString`.
+        // being valid UTF-8 is an invariant of `CappedString`. Since we are returning a `&mut str`
+        // to the caller, the caller cannot safely use it to mutate this `CappedString`'s buffer in
+        // a way that violates the UTF-8 property.
         unsafe { str::from_utf8_unchecked_mut(self.as_bytes_mut()) }
     }
 
+    /// Returns a byte slice containing the UTF-8 bytes representing the string.
+    /// 
+    /// ```
+    /// # use libshire::strings::CappedString;
+    /// # fn main() -> Result<(), libshire::strings::capped::CapacityError> {
+    /// let s = CappedString::<16>::new("hello!")?;
+    /// assert_eq!(s.as_bytes(), &[0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x21]);
+    /// # Ok(())
+    /// # }
+    /// ```
     #[inline]
     #[must_use]
     pub fn as_bytes(&self) -> &[u8] {
@@ -176,8 +447,8 @@ impl<const N: usize> CappedString<N> {
     }
 
     /// # Safety
-    /// The caller is responsible for ensuring that the slice is valid UTF-8 when the mutable
-    /// borrow ends.
+    /// The slice must be valid UTF-8 when the mutable borrow ends and this `CappedString` is used
+    /// again.
     #[inline]
     #[must_use]
     pub unsafe fn as_bytes_mut(&mut self) -> &mut [u8] {
@@ -194,10 +465,14 @@ impl<const N: usize> CappedString<N> {
         unsafe { &mut *(data_slice as *mut [MaybeUninit<u8>] as *mut [u8]) }
     }
 
+    #[inline]
+    #[must_use]
     pub fn len(&self) -> usize {
         usize::from(self.len)
     }
 
+    #[inline]
+    #[must_use]
     pub fn is_empty(&self) -> bool {
         self.len == 0
     }
@@ -205,10 +480,14 @@ impl<const N: usize> CappedString<N> {
 
 #[cfg(feature = "alloc")]
 impl<const N: usize> CappedString<N> {
+    #[inline]
+    #[must_use]
     pub fn into_boxed_str(self) -> Box<str> {
         self.as_str().into()
     }
 
+    #[inline]
+    #[must_use]
     pub fn into_string(self) -> String {
         self.as_str().to_owned()
     }
@@ -266,7 +545,7 @@ impl<const N: usize> borrow::BorrowMut<str> for CappedString<N> {
 }
 
 impl<'a, const N: usize> TryFrom<&'a str> for CappedString<N> {
-    type Error = Error;
+    type Error = CapacityError;
 
     #[inline]
     fn try_from(s: &'a str) -> Result<Self, Self::Error> {
@@ -276,7 +555,7 @@ impl<'a, const N: usize> TryFrom<&'a str> for CappedString<N> {
 
 #[cfg(feature = "alloc")]
 impl<const N: usize> TryFrom<String> for CappedString<N> {
-    type Error = Error;
+    type Error = CapacityError;
 
     #[inline]
     fn try_from(s: String) -> Result<Self, Self::Error> {
@@ -286,7 +565,7 @@ impl<const N: usize> TryFrom<String> for CappedString<N> {
 
 #[cfg(feature = "alloc")]
 impl<const N: usize> TryFrom<Box<str>> for CappedString<N> {
-    type Error = Error;
+    type Error = CapacityError;
 
     #[inline]
     fn try_from(s: Box<str>) -> Result<Self, Self::Error> {
@@ -296,7 +575,7 @@ impl<const N: usize> TryFrom<Box<str>> for CappedString<N> {
 
 #[cfg(feature = "alloc")]
 impl<'a, const N: usize> TryFrom<Cow<'a, str>> for CappedString<N> {
-    type Error = Error;
+    type Error = CapacityError;
 
     #[inline]
     fn try_from(s: Cow<'a, str>) -> Result<Self, Self::Error> {
@@ -351,7 +630,7 @@ impl<const N: usize> Hash for CappedString<N> {
 }
 
 impl<const N: usize> str::FromStr for CappedString<N> {
-    type Err = Error;
+    type Err = CapacityError;
 
     #[inline]
     fn from_str(s: &str) -> Result<Self, Self::Err> {
@@ -373,32 +652,243 @@ impl<const N: usize> fmt::Display for CappedString<N> {
     }
 }
 
-#[derive(Debug)]
-pub struct Error {
-    max_len: usize,
-    actual_len: usize,
-}
-
-impl Error {
-    pub fn max_len(&self) -> usize {
-        self.max_len
-    }
-
-    pub fn actual_len(&self) -> usize {
-        self.actual_len
+/// Returns a pointer to the longest prefix of `src` which is valid UTF-8 and whose length is
+/// less than or equal to `max_len`, and returns the length of this prefix.
+#[inline]
+fn truncate_str(src: &str, max_len: u8) -> (*const u8, u8) {
+    match u8::try_from(src.len()) {
+        // If the length of the `src` string is less than or equal to `max_len`, there is no need to
+        // truncate it.
+        Ok(src_len) if src_len <= max_len => (src.as_ptr(), src_len),
+
+        // If the length of `src` is greater than `max_len`, we need to truncate it. Note that
+        // `u8::try_from` returning an error means that `src.len() > max_len`, since `max_len` is a
+        // `u8` and `src.len()` is a `usize`.
+        _ => {
+            let src = src.as_bytes();
+
+            let mut i = max_len;
+
+            // Find the rightmost codepoint which starts at an index less than or equal to
+            // `max_len`. Everything to the left of this will be valid UTF-8 with a length less
+            // than or equal to `max_len`. We only need to do 3 iterations because codepoints have
+            // a maximum length of 4 bytes.
+            for _ in 0..3 {
+                // The first byte in the string must always be the start of a codepoint.
+                if i == 0 {
+                    break;
+                }
+
+                // SAFETY:
+                // `i <= max_len`, since it is never incremented. If this branch is run, then either
+                // `src.len(): usize` does not fit into a `u8`, in which case it must be greater
+                // than `max_len: u8`, or it does fit into a `u8` but it is greater than `max_len`.
+                // Therefore, `src.len() > max_len` must hold. Substitution gives `i < src.len()`,
+                // so `i` is a valid index into `src`.
+                let byte = unsafe { *src.get_unchecked(usize::from(i)) };
+
+                // If the byte is not of the form 0b10xxxxxx, then it is the start of a codepoint.
+                if byte & 0xc0 != 0x80 {
+                    break;
+                }
+
+                i -= 1;
+            }
+
+            // `i < src.len()` always holds as discussed above, so the pointer `src.as_ptr()` is
+            // valid for reads of `i` bytes. `i` is the index of the start of a codepoint, and
+            // codepoints are contiguous, so the `i` bytes being pointed to must be valid UTF-8.
+            (src.as_ptr(), i)
+        },
     }
 }
 
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(
-            f,
-            "string of length {} exceeds limit for `CappedString<{}>`",
-            self.actual_len,
-            self.max_len
-        )
+#[cfg(test)]
+mod tests {
+    use super::CappedString;
+
+    #[test]
+    fn test_truncate_str() {
+        use super::truncate_str;
+
+        let s1 = "hello";
+        assert_eq!(truncate_str(s1, 0), (s1.as_ptr(), 0));
+        assert_eq!(truncate_str(s1, 1), (s1.as_ptr(), 1));
+        assert_eq!(truncate_str(s1, 5), (s1.as_ptr(), 5));
+        assert_eq!(truncate_str(s1, 6), (s1.as_ptr(), 5));
+
+        let s2 = "こんにちは";
+        assert_eq!(truncate_str(s2, 0), (s2.as_ptr(), 0));
+        assert_eq!(truncate_str(s2, 1), (s2.as_ptr(), 0));
+        assert_eq!(truncate_str(s2, 2), (s2.as_ptr(), 0));
+        assert_eq!(truncate_str(s2, 3), (s2.as_ptr(), 3));
+        assert_eq!(truncate_str(s2, 4), (s2.as_ptr(), 3));
+        assert_eq!(truncate_str(s2, 5), (s2.as_ptr(), 3));
+        assert_eq!(truncate_str(s2, 6), (s2.as_ptr(), 6));
+        assert_eq!(truncate_str(s2, 14), (s2.as_ptr(), 12));
+        assert_eq!(truncate_str(s2, 15), (s2.as_ptr(), 15));
+        assert_eq!(truncate_str(s2, 16), (s2.as_ptr(), 15));
+        assert_eq!(truncate_str(s2, 18), (s2.as_ptr(), 15));
+
+        let s3 = "🤖 こんにちは, world 🤖";
+        assert_eq!(truncate_str(s3, 0), (s3.as_ptr(), 0));
+        assert_eq!(truncate_str(s3, 1), (s3.as_ptr(), 0));
+        assert_eq!(truncate_str(s3, 2), (s3.as_ptr(), 0));
+        assert_eq!(truncate_str(s3, 3), (s3.as_ptr(), 0));
+        assert_eq!(truncate_str(s3, 4), (s3.as_ptr(), 4));
+        assert_eq!(truncate_str(s3, 5), (s3.as_ptr(), 5));
+        assert_eq!(truncate_str(s3, 6), (s3.as_ptr(), 5));
+        assert_eq!(truncate_str(s3, 7), (s3.as_ptr(), 5));
+        assert_eq!(truncate_str(s3, 8), (s3.as_ptr(), 8));
+        assert_eq!(truncate_str(s3, 28), (s3.as_ptr(), 28));
+        assert_eq!(truncate_str(s3, 29), (s3.as_ptr(), 28));
+        assert_eq!(truncate_str(s3, 30), (s3.as_ptr(), 28));
+        assert_eq!(truncate_str(s3, 31), (s3.as_ptr(), 28));
+        assert_eq!(truncate_str(s3, 32), (s3.as_ptr(), 32));
+        assert_eq!(truncate_str(s3, 33), (s3.as_ptr(), 32));
+        assert_eq!(truncate_str(s3, 36), (s3.as_ptr(), 32));
+
+        let s4 = "a";
+        assert_eq!(truncate_str(s4, 0), (s4.as_ptr(), 0));
+        assert_eq!(truncate_str(s4, 1), (s4.as_ptr(), 1));
+        assert_eq!(truncate_str(s4, 2), (s4.as_ptr(), 1));
+        assert_eq!(truncate_str(s4, 3), (s4.as_ptr(), 1));
+        assert_eq!(truncate_str(s4, 4), (s4.as_ptr(), 1));
+
+        let s5 = "";
+        assert_eq!(truncate_str(s5, 0), (s5.as_ptr(), 0));
+        assert_eq!(truncate_str(s5, 1), (s5.as_ptr(), 0));
+        assert_eq!(truncate_str(s5, 2), (s5.as_ptr(), 0));
+        assert_eq!(truncate_str(s5, 3), (s5.as_ptr(), 0));
+        assert_eq!(truncate_str(s5, 4), (s5.as_ptr(), 0));
+
+        let s6 = "На берегу пустынных волн\n\
+                  Стоял он, дум великих полн,\n\
+                  И вдаль глядел. Пред ним широко\n\
+                  Река неслася; бедный чёлн\n\
+                  По ней стремился одиноко.\n\
+                  По мшистым, топким берегам\n\
+                  Чернели избы здесь и там,\n\
+                  Приют убогого чухонца;\n\
+                  И лес, неведомый лучам\n\
+                  В тумане спрятанного солнца,\n\
+                  Кругом шумел.";
+        assert_eq!(truncate_str(s6, 0), (s6.as_ptr(), 0));
+        assert_eq!(truncate_str(s6, 1), (s6.as_ptr(), 0));
+        assert_eq!(truncate_str(s6, 2), (s6.as_ptr(), 2));
+        assert_eq!(truncate_str(s6, 3), (s6.as_ptr(), 2));
+        assert_eq!(truncate_str(s6, 4), (s6.as_ptr(), 4));
+        assert_eq!(truncate_str(s6, 254), (s6.as_ptr(), 253));
+        assert_eq!(truncate_str(s6, 255), (s6.as_ptr(), 255));
+    }
+
+    #[test]
+    fn test_new() {
+        assert_eq!(&*CappedString::<5>::new("").unwrap(), "");
+        assert_eq!(&*CappedString::<5>::new("a").unwrap(), "a");
+        assert_eq!(&*CappedString::<5>::new("hello").unwrap(), "hello");
+        assert_eq!(&*CappedString::<6>::new("hello").unwrap(), "hello");
+        assert!(CappedString::<5>::new("hello!").is_err());
+        assert_eq!(&*CappedString::<6>::new("hello!").unwrap(), "hello!");
+        assert_eq!(&*CappedString::<5>::new("こ").unwrap(), "こ");
+        assert!(CappedString::<5>::new("こん").is_err());
+        assert_eq!(&*CappedString::<6>::new("こん").unwrap(), "こん");
+        assert!(CappedString::<6>::new("こんにちは").is_err());
+        assert_eq!(&*CappedString::<0>::new("").unwrap(), "");
+        assert!(CappedString::<0>::new("a").is_err());
+    }
+
+    #[test]
+    fn test_new_truncating() {
+        assert_eq!(&*CappedString::<5>::new_truncating(""), "");
+        assert_eq!(&*CappedString::<5>::new_truncating("a"), "a");
+        assert_eq!(&*CappedString::<5>::new_truncating("hello"), "hello");
+        assert_eq!(&*CappedString::<6>::new_truncating("hello"), "hello");
+        assert_eq!(&*CappedString::<5>::new_truncating("hello!"), "hello");
+        assert_eq!(&*CappedString::<6>::new_truncating("hello!"), "hello!");
+        assert_eq!(&*CappedString::<5>::new_truncating("こ"), "こ");
+        assert_eq!(&*CappedString::<5>::new_truncating("こん"), "こ");
+        assert_eq!(&*CappedString::<6>::new_truncating("こん"), "こん");
+        assert_eq!(&*CappedString::<6>::new_truncating("こんにちは"), "こん");
+        assert_eq!(&*CappedString::<7>::new_truncating("こんにちは"), "こん");
+        assert_eq!(&*CappedString::<8>::new_truncating("こんにちは"), "こん");
+        assert_eq!(&*CappedString::<9>::new_truncating("こんにちは"), "こんに");
+        assert_eq!(&*CappedString::<3>::new_truncating("🤖 hello 🤖"), "");
+        assert_eq!(&*CappedString::<4>::new_truncating("🤖 hello 🤖"), "🤖");
+        assert_eq!(&*CappedString::<14>::new_truncating("🤖 hello 🤖"), "🤖 hello ");
+        assert_eq!(&*CappedString::<15>::new_truncating("🤖 hello 🤖"), "🤖 hello 🤖");
+        assert_eq!(&*CappedString::<20>::new_truncating("🤖 hello 🤖"), "🤖 hello 🤖");
+        assert_eq!(&*CappedString::<0>::new_truncating(""), "");
+        assert_eq!(&*CappedString::<0>::new_truncating("a"), "");
+    }
+
+    #[test]
+    fn test_push() {
+        let mut s = CappedString::<6>::empty();
+        s.push_str("").unwrap();
+        assert_eq!(&*s, "");
+        s.push('h').unwrap();
+        assert_eq!(&*s, "h");
+        s.push_str("ello").unwrap();
+        assert_eq!(&*s, "hello");
+        assert!(s.push_str(", world").is_err());
+        assert_eq!(&*s, "hello");
+    }
+
+    #[test]
+    fn test_push_truncating() {
+        let mut s = CappedString::<6>::empty();
+
+        s.push_str_truncating("");
+        assert_eq!(&*s, "");
+        s.push_truncating('h');
+        assert_eq!(&*s, "h");
+        s.push_str_truncating("ello");
+        assert_eq!(&*s, "hello");
+        s.push_str_truncating(", world");
+        assert_eq!(&*s, "hello,");
+        
+        s.clear();
+        
+        s.push_truncating('こ');
+        assert_eq!(&*s, "こ");
+        s.push_truncating('ん');
+        assert_eq!(&*s, "こん");
+        s.push_truncating('に');
+        assert_eq!(&*s, "こん");
+
+        s.clear();
+
+        s.push_truncating('🤖');
+        assert_eq!(&*s, "🤖");
+        s.push_truncating('🤖');
+        assert_eq!(&*s, "🤖");
+        s.push_str_truncating("!!!");
+        assert_eq!(&*s, "🤖!!");
+
+        s.clear();
+
+        s.push_str_truncating("🤖 ");
+        assert_eq!(&*s, "🤖 ");
+        s.push_truncating('🤖');
+        assert_eq!(&*s, "🤖 ");
+
+        s.clear();
+
+        s.push_str_truncating("  ");
+        assert_eq!(&*s, "  ");
+        s.push_str_truncating("🤖🤖🤖");
+        assert_eq!(&*s, "  🤖");
+        s.push_truncating('!');
+        assert_eq!(&*s, "  🤖");
+
+        s.clear();
+
+        s.push_str_truncating("   ");
+        assert_eq!(&*s, "   ");
+        s.push_truncating('🤖');
+        assert_eq!(&*s, "   ");
+        s.push_str_truncating("こんにちは");
+        assert_eq!(&*s, "   こ");
     }
 }
-
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
diff --git a/src/strings/mod.rs b/src/strings/mod.rs
index 6facc8d..3825407 100644
--- a/src/strings/mod.rs
+++ b/src/strings/mod.rs
@@ -4,6 +4,6 @@ pub mod capped;
 pub mod inlining;
 
 pub use fixed::{FixedString, Error as FixedStringError};
-pub use capped::{CappedString, Error as CappedStringError};
+pub use capped::{CappedString, CapacityError as CappedStringError};
 #[cfg(feature = "alloc")]
 pub use inlining::{InliningString, InliningString23};