Add error category contains(ec) method.

Author: evoskuil

include/bitcoin/system/error/macros.hpp

@@ -57,6 +57,7 @@ class BC_API cat##_category \
     static const message_map<cat##_t> messages; \
 public: \
     static const cat##_category singleton; \
+    static bool contains(const std::error_code& ec) noexcept; \
     virtual const char* name() const noexcept; \
     virtual std::string message(int condition) const noexcept; \
     virtual std::error_condition default_error_condition(int value) const noexcept; \
@@ -74,6 +75,7 @@ class BC_API cat##_category \
     static const message_map<cat##_t> messages; \
 public: \
     static const cat##_category singleton; \
+    static bool contains(const std::error_code& ec) noexcept; \
     virtual const char* name() const noexcept; \
     virtual std::string message(int condition) const noexcept; \
     virtual std::error_condition default_error_condition(int value) const noexcept; \
@@ -84,6 +86,10 @@ std::error_condition make_error_condition(cat##_t value) noexcept
 
 #define DEFINE_ERROR_T_CATEGORY(cat, category_name, unmapped) \
 const cat##_category cat##_category::singleton; \
+bool cat##_category::contains(const std::error_code& ec) noexcept \
+{ \
+    return is_zero(std::strcmp(ec.category().name(), category_name)); \
+} \
 const char* cat##_category::name() const noexcept \
 { \
     return category_name; \

test/error/error.cpp

@@ -40,7 +40,7 @@ BOOST_AUTO_TEST_CASE(error_t__code__message_overflow__default_message)
 // Overflows can be cast in, and value retained, and yield default message.
 BOOST_AUTO_TEST_CASE(error_t__code__value_overflow__default_message)
 {
-    const auto overflow = static_cast<int>(error::error_last);
+    constexpr auto overflow = static_cast<int>(error::error_last);
     const auto ec = code(static_cast<error::error_t>(overflow));
     BOOST_REQUIRE(ec);
     BOOST_REQUIRE_EQUAL(ec.message(), default_message);
@@ -108,6 +108,14 @@ BOOST_AUTO_TEST_CASE(error_t__code__category_name__expected)
 {
     BOOST_REQUIRE_EQUAL(code().category().name(), system_category_name);
     BOOST_REQUIRE_EQUAL(code(error::success).category().name(), bitcoin_category_name);
+    BOOST_REQUIRE_NE(code(error::script_success).category().name(), code(error::success).category().name());
+}
+
+BOOST_AUTO_TEST_CASE(error_t__code__category_contains__expected)
+{
+    BOOST_REQUIRE(system::error::error_category::contains(system::error::success));
+    BOOST_REQUIRE(!system::error::script_error_category::contains(system::error::success));
+    BOOST_REQUIRE(system::error::script_error_category::contains(system::error::script_success));
 }
 
 BOOST_AUTO_TEST_CASE(error_t__code__default_error_condition_category_name__expected)