Replace impl_to_hex_from_lower_hex with deprecated inherent to_hex

diff --git a/crypto/src/ecdsa.rs b/crypto/src/ecdsa.rs
index 527db78a..58ad265d 100644
--- a/crypto/src/ecdsa.rs
+++ b/crypto/src/ecdsa.rs
@@ -4,6 +4,9 @@
 //!
 //! This module provides ECDSA signatures used by Bitcoin that can be roundtrip (de)serialized.
 
+#[cfg(feature = "hex")]
+#[cfg(feature = "alloc")]
+use alloc::string::String;
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
 use core::borrow::Borrow;
@@ -19,9 +22,6 @@ use core::str::FromStr;
 use arbitrary::{Arbitrary, Unstructured};
 #[cfg(feature = "hex")]
 use hex::DisplayHex;
-#[cfg(feature = "hex")]
-#[cfg(feature = "alloc")]
-use internals::impl_to_hex_from_lower_hex;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
@@ -161,6 +161,12 @@ impl SerializedSignature {
     /// Returns an iterator over bytes of the signature.
     #[inline]
     pub fn iter(&self) -> core::slice::Iter<'_, u8> { self.into_iter() }
+
+    /// Gets the hex representation of this type.
+    #[cfg(feature = "hex")]
+    #[cfg(feature = "alloc")]
+    #[deprecated(since = "TBD", note = "use `format!(\"{var:x}\")` instead")]
+    pub fn to_hex(&self) -> String { alloc::format!("{:x}", self) }
 }
 
 impl fmt::Debug for SerializedSignature {
@@ -193,10 +199,6 @@ impl fmt::LowerHex for SerializedSignature {
         fmt::LowerHex::fmt(&(**self).as_hex(), f)
     }
 }
-#[cfg(feature = "hex")]
-#[cfg(feature = "alloc")]
-impl_to_hex_from_lower_hex!(SerializedSignature, |signature: &SerializedSignature| signature.len
-    * 2);
 
 #[cfg(feature = "hex")]
 impl fmt::UpperHex for SerializedSignature {
diff --git a/crypto/src/key.rs b/crypto/src/key.rs
index d36f1cf0..851210b2 100644
--- a/crypto/src/key.rs
+++ b/crypto/src/key.rs
@@ -21,8 +21,6 @@ use hex::DisplayHex;
 #[cfg(feature = "alloc")]
 use internals::array::ArrayExt;
 use internals::array_vec::ArrayVec;
-#[cfg(feature = "alloc")]
-use internals::impl_to_hex_from_lower_hex;
 use network::NetworkKind;
 #[cfg(feature = "rand")]
 #[cfg(feature = "std")]
@@ -450,6 +448,11 @@ impl XOnlyPublicKey {
             Err(_) => Err(TweakXOnlyPublicKeyError::ResultKeyInvalid),
         }
     }
+
+    /// Gets the hex representation of this type.
+    #[cfg(feature = "alloc")]
+    #[deprecated(since = "TBD", note = "use `format!(\"{var:x}\")` instead")]
+    pub fn to_hex(&self) -> String { alloc::format!("{:x}", self) }
 }
 
 impl FromStr for XOnlyPublicKey {
@@ -494,9 +497,6 @@ impl fmt::LowerHex for XOnlyPublicKey {
     #[inline]
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { self.to_inner().fmt(f) }
 }
-// Allocate for serialized size
-#[cfg(feature = "alloc")]
-impl_to_hex_from_lower_hex!(XOnlyPublicKey, |_| constants::SCHNORR_PUBLIC_KEY_SIZE * 2);
 
 impl fmt::Display for XOnlyPublicKey {
     #[inline]
@@ -1495,15 +1495,17 @@ impl TweakedPublicKey {
     pub fn serialize(&self) -> [u8; constants::SCHNORR_PUBLIC_KEY_SIZE] {
         self.as_x_only_public_key().serialize().0
     }
+
+    /// Gets the hex representation of this type.
+    #[cfg(feature = "alloc")]
+    #[deprecated(since = "TBD", note = "use `format!(\"{var:x}\")` instead")]
+    pub fn to_hex(&self) -> String { alloc::format!("{:x}", self) }
 }
 
 impl fmt::LowerHex for TweakedPublicKey {
     #[inline]
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { self.as_x_only_public_key().fmt(f) }
 }
-// Allocate for serialized size
-#[cfg(feature = "alloc")]
-impl_to_hex_from_lower_hex!(TweakedPublicKey, |_| constants::SCHNORR_PUBLIC_KEY_SIZE * 2);
 
 impl fmt::Display for TweakedPublicKey {
     #[inline]
diff --git a/crypto/src/taproot.rs b/crypto/src/taproot.rs
index 2cd0bab5..7d6b182d 100644
--- a/crypto/src/taproot.rs
+++ b/crypto/src/taproot.rs
@@ -4,6 +4,9 @@
 //!
 //! This module provides Taproot signatures used by Bitcoin that can be roundtrip (de)serialized.
 
+#[cfg(feature = "hex")]
+#[cfg(feature = "alloc")]
+use alloc::string::String;
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
 use core::borrow::Borrow;
@@ -15,9 +18,6 @@ use core::str::FromStr;
 #[cfg(feature = "arbitrary")]
 use arbitrary::{Arbitrary, Unstructured};
 use internals::array::ArrayExt;
-#[cfg(feature = "alloc")]
-#[cfg(feature = "hex")]
-use internals::impl_to_hex_from_lower_hex;
 
 pub use self::into_iter::IntoIter;
 #[cfg(feature = "hex")]
@@ -220,6 +220,12 @@ impl SerializedSignature {
     /// Set the length of the object.
     #[inline]
     pub(crate) fn set_len_unchecked(&mut self, len: usize) { self.len = len; }
+
+    /// Gets the hex representation of this type.
+    #[cfg(feature = "hex")]
+    #[cfg(feature = "alloc")]
+    #[deprecated(since = "TBD", note = "use `format!(\"{var:x}\")` instead")]
+    pub fn to_hex(&self) -> String { alloc::format!("{:x}", self) }
 }
 
 impl fmt::Debug for SerializedSignature {
@@ -250,10 +256,6 @@ impl fmt::LowerHex for SerializedSignature {
     #[inline]
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { self.fmt_internal(f, hex::Case::Lower) }
 }
-#[cfg(feature = "alloc")]
-#[cfg(feature = "hex")]
-impl_to_hex_from_lower_hex!(SerializedSignature, |signature: &SerializedSignature| signature.len
-    * 2);
 
 #[cfg(feature = "hex")]
 impl fmt::UpperHex for SerializedSignature {
diff --git a/internals/src/macros.rs b/internals/src/macros.rs
index 1486ce53..d9b3a9b6 100644
--- a/internals/src/macros.rs
+++ b/internals/src/macros.rs
@@ -15,26 +15,6 @@ macro_rules! const_assert {
     }
 }
 
-/// Adds an implementation of `pub fn to_hex(&self) -> String`.
-///
-/// The added function allocates a `String` then calls through to [`core::fmt::LowerHex`].
-#[macro_export]
-macro_rules! impl_to_hex_from_lower_hex {
-    ($t:ident, $hex_len_fn:expr) => {
-        impl $t {
-            /// Gets the hex representation of this type
-            pub fn to_hex(&self) -> alloc::string::String {
-                use core::fmt::Write;
-
-                let mut hex_string = alloc::string::String::with_capacity($hex_len_fn(self));
-                write!(&mut hex_string, "{:x}", self).expect("writing to string shouldn't fail");
-
-                hex_string
-            }
-        }
-    };
-}
-
 /// Constructs a transparent wrapper around an inner type and soundly implements reference casts.
 ///
 /// This macro takes care of several issues related to newtypes that need to allow casting their
diff --git a/p2p/src/lib.rs b/p2p/src/lib.rs
index a45b9561..fe362766 100644
--- a/p2p/src/lib.rs
+++ b/p2p/src/lib.rs
@@ -40,6 +40,7 @@ pub extern crate arbitrary;
 pub extern crate hex;
 
 use alloc::borrow::ToOwned;
+use alloc::string::String;
 use core::borrow::{Borrow, BorrowMut};
 use core::str::FromStr;
 use core::{fmt, ops};
@@ -47,7 +48,6 @@ use core::{fmt, ops};
 #[cfg(feature = "arbitrary")]
 use arbitrary::{Arbitrary, Unstructured};
 use encoding::{ArrayDecoder, ArrayEncoder};
-use internals::impl_to_hex_from_lower_hex;
 use network::{Network, TestnetVersion};
 
 #[rustfmt::skip]
@@ -215,13 +215,15 @@ impl ServiceFlags {
 
     /// Gets the integer representation of this [`ServiceFlags`].
     pub fn to_u64(self) -> u64 { self.0 }
+
+    /// Gets the hex representation of this type.
+    #[deprecated(since = "TBD", note = "use `format!(\"{var:x}\")` instead")]
+    pub fn to_hex(&self) -> String { alloc::format!("{:x}", self) }
 }
 
 impl fmt::LowerHex for ServiceFlags {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::LowerHex::fmt(&self.0, f) }
 }
-impl_to_hex_from_lower_hex!(ServiceFlags, |service_flags: &ServiceFlags| 16
-    - service_flags.0.leading_zeros() as usize / 4);
 
 impl fmt::UpperHex for ServiceFlags {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { fmt::UpperHex::fmt(&self.0, f) }
@@ -349,6 +351,10 @@ impl Magic {
 
     /// Gets network magic bytes.
     pub fn to_bytes(self) -> [u8; 4] { self.0 }
+
+    /// Gets the hex representation of this type.
+    #[deprecated(since = "TBD", note = "use `format!(\"{var:x}\")` instead")]
+    pub fn to_hex(&self) -> String { alloc::format!("{:x}", self) }
 }
 
 impl FromStr for Magic {
@@ -406,7 +412,6 @@ impl fmt::LowerHex for Magic {
         Ok(())
     }
 }
-impl_to_hex_from_lower_hex!(Magic, |_| 8);
 
 impl fmt::UpperHex for Magic {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
diff --git a/taproot-primitives/src/lib.rs b/taproot-primitives/src/lib.rs
index cb972688..d92520b4 100644
--- a/taproot-primitives/src/lib.rs
+++ b/taproot-primitives/src/lib.rs
@@ -32,6 +32,8 @@ pub extern crate serde;
 #[doc(no_inline)]
 pub use self::error::InvalidTaprootLeafVersionError;
 
+#[cfg(feature = "alloc")]
+use alloc::string::String;
 use core::fmt;
 
 #[cfg(feature = "arbitrary")]
@@ -158,6 +160,11 @@ impl LeafVersion {
             Self::Future(version) => version.to_consensus(),
         }
     }
+
+    /// Gets the hex representation of this type.
+    #[cfg(feature = "alloc")]
+    #[deprecated(since = "TBD", note = "use `format!(\"{var:x}\")` instead")]
+    pub fn to_hex(&self) -> String { alloc::format!("{:x}", self) }
 }
 
 impl fmt::Display for LeafVersion {
@@ -176,8 +183,6 @@ impl fmt::LowerHex for LeafVersion {
         fmt::LowerHex::fmt(&self.to_consensus(), f)
     }
 }
-#[cfg(feature = "alloc")]
-internals::impl_to_hex_from_lower_hex!(LeafVersion, |_| 2);
 
 impl fmt::UpperHex for LeafVersion {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -257,6 +262,11 @@ impl FutureLeafVersion {
     /// Returns the consensus representation of this [`FutureLeafVersion`].
     #[inline]
     pub fn to_consensus(self) -> u8 { self.0 }
+
+    /// Gets the hex representation of this type.
+    #[cfg(feature = "alloc")]
+    #[deprecated(since = "TBD", note = "use `format!(\"{var:x}\")` instead")]
+    pub fn to_hex(&self) -> String { alloc::format!("{:x}", self) }
 }
 
 impl fmt::Display for FutureLeafVersion {
@@ -268,8 +278,6 @@ impl fmt::LowerHex for FutureLeafVersion {
     #[inline]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { fmt::LowerHex::fmt(&self.0, f) }
 }
-#[cfg(feature = "alloc")]
-internals::impl_to_hex_from_lower_hex!(FutureLeafVersion, |_| 2);
 
 impl fmt::UpperHex for FutureLeafVersion {
     #[inline]