C++: Conversion {address, bytes32} → bytes_view

ethereum · May 6, 2022 · ed16827 · ed16827
1 parent a9662e3
commit ed16827
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Showing 2 changed files with 44 additions and 5 deletions.
diff --git a/include/evmc/evmc.hpp b/include/evmc/evmc.hpp
@@ -9,6 +9,7 @@
 #include <functional>
 #include <initializer_list>
 #include <ostream>
+#include <string_view>
 #include <utility>
 
 static_assert(EVMC_LATEST_STABLE_REVISION <= EVMC_MAX_REVISION,
@@ -18,6 +19,9 @@ static_assert(EVMC_LATEST_STABLE_REVISION <= EVMC_MAX_REVISION,
 /// @ingroup cpp
 namespace evmc
 {
+/// String view of uint8_t chars.
+using bytes_view = std::basic_string_view<uint8_t>;
+
 /// The big-endian 160-bit hash suitable for keeping an Ethereum address.
 ///
 /// This type wraps C ::evmc_address to make sure objects of this type are always initialized.
@@ -57,6 +61,9 @@ struct address : evmc_address
 
     /// Explicit operator converting to bool.
     inline constexpr explicit operator bool() const noexcept;
+
+    /// Implicit operator converting to bytes_view.
+    inline constexpr operator bytes_view() const noexcept { return {bytes, sizeof(bytes)}; }
 };
 
 /// The fixed size array of 32 bytes for storing 256-bit EVM values.
@@ -109,7 +116,10 @@ struct bytes32 : evmc_bytes32
     {}
 
     /// Explicit operator converting to bool.
-    constexpr inline explicit operator bool() const noexcept;
+    inline constexpr explicit operator bool() const noexcept;
+
+    /// Implicit operator converting to bytes_view.
+    inline constexpr operator bytes_view() const noexcept { return {bytes, sizeof(bytes)}; }
 };
 
 /// The alias for evmc::bytes32 to represent a big-endian 256-bit integer.

diff --git a/test/unittests/cpp_test.cpp b/test/unittests/cpp_test.cpp
@@ -415,6 +415,29 @@ TEST(cpp, address_from_uint)
     EXPECT_EQ(address{0xc1c2c3c4c5c6c7c8}, 0x000000000000000000000000c1c2c3c4c5c6c7c8_address);
 }
 
+TEST(cpp, address_to_bytes_view)
+{
+    using evmc::operator""_address;
+
+    constexpr auto a = 0xa0a1a2a3a4a5a6a7a8a9b0b1b2b3b4b5b6b7b8b9_address;
+    static_assert(evmc::bytes_view{a}.size() == 20);
+    const evmc::bytes_view v = a;
+    EXPECT_EQ(v, (evmc::bytes{0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9,
+                              0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9}));
+}
+
+TEST(cpp, bytes32_to_bytes_view)
+{
+    using evmc::operator""_bytes32;
+
+    constexpr auto b = 0xa0a1a2a3a4a5a6a7a8a9b0b1b2b3b4b5b6b7b8b9c0c1c2c3c4c5c6c7c8c9d0d1_bytes32;
+    static_assert(evmc::bytes_view{b}.size() == 32);
+    const evmc::bytes_view v = b;
+    EXPECT_EQ(v, (evmc::bytes{0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xb0,
+                              0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xc0, 0xc1,
+                              0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xd0, 0xd1}));
+}
+
 TEST(cpp, result)
 {
     static const uint8_t output = 0;
@@ -796,8 +819,11 @@ TEST(cpp, status_code_to_string)
     };
 
 // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
-#define TEST_CASE(STATUS_CODE) \
-    TestCase { STATUS_CODE, #STATUS_CODE }
+#define TEST_CASE(STATUS_CODE)    \
+    TestCase                      \
+    {                             \
+        STATUS_CODE, #STATUS_CODE \
+    }
     constexpr TestCase test_cases[]{
         TEST_CASE(EVMC_SUCCESS),
         TEST_CASE(EVMC_FAILURE),
@@ -847,8 +873,11 @@ TEST(cpp, revision_to_string)
     };
 
 // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
-#define TEST_CASE(STATUS_CODE) \
-    TestCase { STATUS_CODE, #STATUS_CODE }
+#define TEST_CASE(STATUS_CODE)    \
+    TestCase                      \
+    {                             \
+        STATUS_CODE, #STATUS_CODE \
+    }
     constexpr TestCase test_cases[]{
         TEST_CASE(EVMC_FRONTIER),
         TEST_CASE(EVMC_HOMESTEAD),