clean up docs, use constexpr

doc/hash2/reference.adoc

@@ -34,3 +34,4 @@ include::reference/ripemd.adoc[]
 ## hash_append
 
 ### <boost/hash2/hash_append.hpp>
+

doc/hash2/reference/sha2.adoc

@@ -32,7 +32,7 @@ using hmac_sha2_512_224 = hmac<sha2_512_224>;
 } // namespace boost
 ```
 
-This header implements the https://csrc.nist.gov/pubs/fips/180-4/upd1/final[sha-2] family of functions.
+This header implements the https://csrc.nist.gov/pubs/fips/180-4/upd1/final[SHA-2] family of functions.
 
 ## sha2_256
 
@@ -42,7 +42,7 @@ class sha2_256
     using result_type = std::array<unsigned char, 32>;
     using size_type = std::uint64_t;
 
-    static const int block_size = 64;
+    static constexpr int block_size = 64;
 
     sha2_256();
     explicit sha2_256( std::uint64_t seed );
@@ -127,7 +127,7 @@ using result_type = std::array<unsigned char, 28>;
 
 Otherwise, all other operations and constants are identical.
 
-The message digest is obtained by truncating the final results of the SHA-256 algorithm to its left-most 224 bits.
+The message digest is obtained by truncating the final results of the SHA-256 algorithm to its leftmost 224 bits.
 
 ## sha2_512
 
@@ -137,7 +137,7 @@ class sha2_512
     using result_type = std::array<unsigned char, 64>;
     using size_type = std::uint64_t;
 
-    static const int block_size = 128;
+    static constexpr int block_size = 128;
 
     sha2_512();
     explicit sha2_512( std::uint64_t seed );
@@ -222,7 +222,7 @@ using result_type = std::array<unsigned char, 48>;
 
 Otherwise, all other operations and constants are identical.
 
-The message digest is obtained by truncating the final results of the SHA-512 algorithm to its left-most 384 bits.
+The message digest is obtained by truncating the final results of the SHA-512 algorithm to its leftmost 384 bits.
 
 ## sha2_512_224
 
@@ -235,7 +235,7 @@ using result_type = std::array<unsigned char, 28>;
 
 Otherwise, all other operations and constants are identical.
 
-The message digest is obtained by truncating the final results of the SHA-512 algorithm to its left-most 224 bits.
+The message digest is obtained by truncating the final results of the SHA-512 algorithm to its leftmost 224 bits.
 
 ## sha2_512_256
 
@@ -248,4 +248,4 @@ using result_type = std::array<unsigned char, 32>;
 
 Otherwise, all other operations and constants are identical.
 
-The message digest is obtained by truncating the final results of the SHA-512 algorithm to its left-most 256 bits.
+The message digest is obtained by truncating the final results of the SHA-512 algorithm to its leftmost 256 bits.

include/boost/hash2/sha2.hpp

@@ -30,7 +30,7 @@ struct sha2_base
 {
     Word state_[ 8 ];
 
-    static int const N = M;
+    static constexpr int N = M;
 
     unsigned char buffer_[ N ];
     std::size_t m_; // == n_ % N
@@ -317,7 +317,7 @@ class sha2_256 : detail::sha2_256_base
     using result_type = std::array<unsigned char, 32>;
     using size_type = std::uint64_t;
 
-    static const int block_size = 64;
+    static constexpr int block_size = 64;
 
     sha2_256()
     {
@@ -393,7 +393,7 @@ class sha2_224 : detail::sha2_256_base
     using result_type = std::array<unsigned char, 28>;
     using size_type = std::uint64_t;
 
-    static int const block_size = 64;
+    static constexpr int block_size = 64;
 
     sha2_224()
     {
@@ -472,7 +472,7 @@ class sha2_512 : detail::sha2_512_base
 
     using detail::sha2_512_base::update;
 
-    static int const block_size = 128;
+    static constexpr int block_size = 128;
 
     sha2_512()
     {
@@ -548,7 +548,7 @@ class sha2_384 : detail::sha2_512_base
     using result_type = std::array<unsigned char, 48>;
     using size_type = std::uint64_t;
 
-    static int const block_size = 128;
+    static constexpr int block_size = 128;
 
     using detail::sha2_512_base::update;
 
@@ -626,7 +626,7 @@ class sha2_512_224 : detail::sha2_512_base
     using result_type = std::array<unsigned char, 28>;
     using size_type = std::uint64_t;
 
-    static int const block_size = 128;
+    static constexpr int block_size = 128;
 
     using detail::sha2_512_base::update;
 
@@ -705,7 +705,7 @@ class sha2_512_256 : detail::sha2_512_base
     using result_type = std::array<unsigned char, 32>;
     using size_type = std::uint64_t;
 
-    static int const block_size = 128;
+    static constexpr int block_size = 128;
 
     using detail::sha2_512_base::update;