Use class instead of struct for objects with member functions

Flagged by Sonar and quite reasonable

13 files changed, 183 insertions, 156 deletions

diff --git a/src/lib/asn1/asn1_obj.h b/src/lib/asn1/asn1_obj.h
index 65a4919fd..63c7dc2e3 100644
--- a/src/lib/asn1/asn1_obj.h
+++ b/src/lib/asn1/asn1_obj.h
@@ -115,18 +115,20 @@ bool maybe_BER(DataSource& src);
 /**
 * General BER Decoding Error Exception
 */
-struct BOTAN_PUBLIC_API(2,0) BER_Decoding_Error : public Decoding_Error
+class BOTAN_PUBLIC_API(2,0) BER_Decoding_Error : public Decoding_Error
    {
-   explicit BER_Decoding_Error(const std::string&);
+   public:
+      explicit BER_Decoding_Error(const std::string&);
    };
 
 /**
 * Exception For Incorrect BER Taggings
 */
-struct BOTAN_PUBLIC_API(2,0) BER_Bad_Tag final : public BER_Decoding_Error
+class BOTAN_PUBLIC_API(2,0) BER_Bad_Tag final : public BER_Decoding_Error
    {
-   BER_Bad_Tag(const std::string& msg, ASN1_Tag tag);
-   BER_Bad_Tag(const std::string& msg, ASN1_Tag tag1, ASN1_Tag tag2);
+   public:
+      BER_Bad_Tag(const std::string& msg, ASN1_Tag tag);
+      BER_Bad_Tag(const std::string& msg, ASN1_Tag tag1, ASN1_Tag tag2);
    };
 
 }
diff --git a/src/lib/ffi/ffi_cipher.cpp b/src/lib/ffi/ffi_cipher.cpp
index 23e277166..44e42aa29 100644
--- a/src/lib/ffi/ffi_cipher.cpp
+++ b/src/lib/ffi/ffi_cipher.cpp
@@ -12,10 +12,11 @@ extern "C" {
 
 using namespace Botan_FFI;
 
-struct botan_cipher_struct final : public botan_struct<Botan::Cipher_Mode, 0xB4A2BF9C>
+class botan_cipher_struct final : public botan_struct<Botan::Cipher_Mode, 0xB4A2BF9C>
    {
-   explicit botan_cipher_struct(Botan::Cipher_Mode* x) : botan_struct(x) {}
-   Botan::secure_vector<uint8_t> m_buf;
+   public:
+      explicit botan_cipher_struct(Botan::Cipher_Mode* x) : botan_struct(x) {}
+      Botan::secure_vector<uint8_t> m_buf;
    };
 
 int botan_cipher_init(botan_cipher_t* cipher, const char* cipher_name, uint32_t flags)
diff --git a/src/lib/ffi/ffi_util.h b/src/lib/ffi/ffi_util.h
index 7f959259c..eb6d22786 100644
--- a/src/lib/ffi/ffi_util.h
+++ b/src/lib/ffi/ffi_util.h
@@ -25,7 +25,7 @@ class FFI_Error final : public Botan::Exception
    };
 
 template<typename T, uint32_t MAGIC>
-struct botan_struct
+class botan_struct
    {
    public:
       botan_struct(T* obj) : m_magic(MAGIC), m_obj(obj) {}
@@ -46,7 +46,7 @@ struct botan_struct
    };
 
 #define BOTAN_FFI_DECLARE_STRUCT(NAME, TYPE, MAGIC) \
-   struct NAME final : public botan_struct<TYPE, MAGIC> { explicit NAME(TYPE* x) : botan_struct(x) {} }
+   class NAME final : public botan_struct<TYPE, MAGIC> { public: explicit NAME(TYPE* x) : botan_struct(x) {} }
 
 // Declared in ffi.cpp
 int ffi_error_exception_thrown(const char* func_name, const char* exn);
diff --git a/src/lib/filters/basefilt.h b/src/lib/filters/basefilt.h
index 40ce0ec6e..01bcad756 100644
--- a/src/lib/filters/basefilt.h
+++ b/src/lib/filters/basefilt.h
@@ -20,11 +20,12 @@ namespace Botan {
 /**
 * BitBucket is a filter which simply discards all inputs
 */
-struct BOTAN_PUBLIC_API(2,0) BitBucket final : public Filter
+class BOTAN_PUBLIC_API(2,0) BitBucket final : public Filter
    {
-   void write(const uint8_t[], size_t) override {}
+   public:
+      void write(const uint8_t[], size_t) override {}
 
-   std::string name() const override { return "BitBucket"; }
+      std::string name() const override { return "BitBucket"; }
    };
 
 /**
diff --git a/src/lib/filters/pipe.h b/src/lib/filters/pipe.h
index 060b5c1ca..cd446bd7e 100644
--- a/src/lib/filters/pipe.h
+++ b/src/lib/filters/pipe.h
@@ -38,16 +38,17 @@ class BOTAN_PUBLIC_API(2,0) Pipe final : public DataSource
       * Exception if you use an invalid message as an argument to
       * read, remaining, etc
       */
-      struct BOTAN_PUBLIC_API(2,0) Invalid_Message_Number final : public Invalid_Argument
+      class BOTAN_PUBLIC_API(2,0) Invalid_Message_Number final : public Invalid_Argument
          {
-         /**
-         * @param where the error occurred
-         * @param msg the invalid message id that was used
-         */
-         Invalid_Message_Number(const std::string& where, message_id msg) :
-            Invalid_Argument("Pipe::" + where + ": Invalid message number " +
-                             std::to_string(msg))
-            {}
+         public:
+            /**
+            * @param where the error occurred
+            * @param msg the invalid message id that was used
+            */
+            Invalid_Message_Number(const std::string& where, message_id msg) :
+               Invalid_Argument("Pipe::" + where + ": Invalid message number " +
+                                std::to_string(msg))
+               {}
          };
 
       /**
diff --git a/src/lib/math/ec_gfp/point_gfp.h b/src/lib/math/ec_gfp/point_gfp.h
index 1d36ad2f4..61239df80 100644
--- a/src/lib/math/ec_gfp/point_gfp.h
+++ b/src/lib/math/ec_gfp/point_gfp.h
@@ -19,20 +19,22 @@ namespace Botan {
 * Exception thrown if you try to convert a zero point to an affine
 * coordinate
 */
-struct BOTAN_PUBLIC_API(2,0) Illegal_Transformation final : public Exception
+class BOTAN_PUBLIC_API(2,0) Illegal_Transformation final : public Exception
    {
-   explicit Illegal_Transformation(const std::string& err =
-                          "Requested transformation is not possible") :
-      Exception(err) {}
+   public:
+      explicit Illegal_Transformation(const std::string& err =
+                                      "Requested transformation is not possible") :
+         Exception(err) {}
    };
 
 /**
 * Exception thrown if some form of illegal point is decoded
 */
-struct BOTAN_PUBLIC_API(2,0) Illegal_Point final : public Exception
+class BOTAN_PUBLIC_API(2,0) Illegal_Point final : public Exception
    {
-   explicit Illegal_Point(const std::string& err = "Malformed ECP point detected") :
-      Exception(err) {}
+   public:
+      explicit Illegal_Point(const std::string& err = "Malformed ECP point detected") :
+         Exception(err) {}
    };
 
 /**
diff --git a/src/lib/pubkey/mce/code_based_key_gen.cpp b/src/lib/pubkey/mce/code_based_key_gen.cpp
index 7377bc117..01650af26 100644
--- a/src/lib/pubkey/mce/code_based_key_gen.cpp
+++ b/src/lib/pubkey/mce/code_based_key_gen.cpp
@@ -19,7 +19,7 @@ namespace Botan {
 
 namespace {
 
-struct binary_matrix
+class binary_matrix
    {
    public:
       binary_matrix(uint32_t m_rown, uint32_t m_coln);
diff --git a/src/lib/pubkey/mce/polyn_gf2m.h b/src/lib/pubkey/mce/polyn_gf2m.h
index 987e1cffe..dd7c1081c 100644
--- a/src/lib/pubkey/mce/polyn_gf2m.h
+++ b/src/lib/pubkey/mce/polyn_gf2m.h
@@ -20,7 +20,7 @@ namespace Botan {
 
 class RandomNumberGenerator;
 
-struct polyn_gf2m
+class polyn_gf2m
    {
    public:
       /**
diff --git a/src/lib/pubkey/pkcs8.h b/src/lib/pubkey/pkcs8.h
index c97fda0e3..0bc9a18f1 100644
--- a/src/lib/pubkey/pkcs8.h
+++ b/src/lib/pubkey/pkcs8.h
@@ -23,10 +23,11 @@ class RandomNumberGenerator;
 /**
 * PKCS #8 General Exception
 */
-struct BOTAN_PUBLIC_API(2,0) PKCS8_Exception final : public Decoding_Error
+class BOTAN_PUBLIC_API(2,0) PKCS8_Exception final : public Decoding_Error
    {
-   explicit PKCS8_Exception(const std::string& error) :
-      Decoding_Error("PKCS #8: " + error) {}
+   public:
+      explicit PKCS8_Exception(const std::string& error) :
+         Decoding_Error("PKCS #8: " + error) {}
    };
 
 /**
diff --git a/src/lib/tls/tls_exceptn.h b/src/lib/tls/tls_exceptn.h
index 1b58e1beb..572ff1885 100644
--- a/src/lib/tls/tls_exceptn.h
+++ b/src/lib/tls/tls_exceptn.h
@@ -34,10 +34,11 @@ class BOTAN_PUBLIC_API(2,0) TLS_Exception : public Exception
 /**
 * Unexpected_Message Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Unexpected_Message final : public TLS_Exception
+class BOTAN_PUBLIC_API(2,0) Unexpected_Message final : public TLS_Exception
    {
-   explicit Unexpected_Message(const std::string& err) :
-      TLS_Exception(Alert::UNEXPECTED_MESSAGE, err) {}
+   public:
+      explicit Unexpected_Message(const std::string& err) :
+         TLS_Exception(Alert::UNEXPECTED_MESSAGE, err) {}
    };
 
 }
diff --git a/src/lib/utils/calendar.h b/src/lib/utils/calendar.h
index 5cf59eccc..665022599 100644
--- a/src/lib/utils/calendar.h
+++ b/src/lib/utils/calendar.h
@@ -18,50 +18,51 @@ namespace Botan {
 /**
 * Struct representing a particular date and time
 */
-struct BOTAN_PUBLIC_API(2,0) calendar_point
+class BOTAN_PUBLIC_API(2,0) calendar_point
    {
-   /** The year */
-   uint32_t year;
+   public:
+      /** The year */
+      uint32_t year;
 
-   /** The month, 1 through 12 for Jan to Dec */
-   uint32_t month;
+      /** The month, 1 through 12 for Jan to Dec */
+      uint32_t month;
 
-   /** The day of the month, 1 through 31 (or 28 or 30 based on month */
-   uint32_t day;
+      /** The day of the month, 1 through 31 (or 28 or 30 based on month */
+      uint32_t day;
 
-   /** Hour in 24-hour form, 0 to 23 */
-   uint32_t hour;
+      /** Hour in 24-hour form, 0 to 23 */
+      uint32_t hour;
 
-   /** Minutes in the hour, 0 to 60 */
-   uint32_t minutes;
+      /** Minutes in the hour, 0 to 60 */
+      uint32_t minutes;
 
-   /** Seconds in the minute, 0 to 60, but might be slightly
-       larger to deal with leap seconds on some systems
-   */
-   uint32_t seconds;
+      /** Seconds in the minute, 0 to 60, but might be slightly
+          larger to deal with leap seconds on some systems
+      */
+      uint32_t seconds;
 
-   /**
-   * Initialize a calendar_point
-   * @param y the year
-   * @param mon the month
-   * @param d the day
-   * @param h the hour
-   * @param min the minute
-   * @param sec the second
-   */
-   calendar_point(uint32_t y, uint32_t mon, uint32_t d, uint32_t h, uint32_t min, uint32_t sec) :
-      year(y), month(mon), day(d), hour(h), minutes(min), seconds(sec) {}
+      /**
+      * Initialize a calendar_point
+      * @param y the year
+      * @param mon the month
+      * @param d the day
+      * @param h the hour
+      * @param min the minute
+      * @param sec the second
+      */
+      calendar_point(uint32_t y, uint32_t mon, uint32_t d, uint32_t h, uint32_t min, uint32_t sec) :
+         year(y), month(mon), day(d), hour(h), minutes(min), seconds(sec) {}
 
-   /**
-   * Returns an STL timepoint object
-   */
-   std::chrono::system_clock::time_point to_std_timepoint() const;
+      /**
+      * Returns an STL timepoint object
+      */
+      std::chrono::system_clock::time_point to_std_timepoint() const;
 
-   /**
-   * Returns a human readable string of the struct's components.
-   * Formatting might change over time. Currently it is RFC339 'iso-date-time'.
-   */
-   std::string to_string() const;
+      /**
+      * Returns a human readable string of the struct's components.
+      * Formatting might change over time. Currently it is RFC339 'iso-date-time'.
+      */
+      std::string to_string() const;
    };
 
 /**
diff --git a/src/lib/utils/exceptn.h b/src/lib/utils/exceptn.h
index 5242e87d9..e5432e43b 100644
--- a/src/lib/utils/exceptn.h
+++ b/src/lib/utils/exceptn.h
@@ -49,202 +49,218 @@ class BOTAN_PUBLIC_API(2,0) Invalid_Argument : public Exception
 * An argument that is invalid because it is not supported by Botan.
 * It might or might not be valid in another context like a standard.
 */
-struct BOTAN_PUBLIC_API(2,0) Unsupported_Argument final : public Invalid_Argument
+class BOTAN_PUBLIC_API(2,0) Unsupported_Argument final : public Invalid_Argument
    {
-   explicit Unsupported_Argument(const std::string& msg) : Invalid_Argument(msg) {}
+   public:
+      explicit Unsupported_Argument(const std::string& msg) : Invalid_Argument(msg) {}
    };
 
 /**
 * Invalid_State Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Invalid_State : public Exception
+class BOTAN_PUBLIC_API(2,0) Invalid_State : public Exception
    {
-   explicit Invalid_State(const std::string& err) :
-      Exception(err)
-      {}
+   public:
+      explicit Invalid_State(const std::string& err) : Exception(err) {}
    };
 
 /**
 * Lookup_Error Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Lookup_Error : public Exception
+class BOTAN_PUBLIC_API(2,0) Lookup_Error : public Exception
    {
-   explicit Lookup_Error(const std::string& err) :
-      Exception(err)
-      {}
+   public:
+      explicit Lookup_Error(const std::string& err) : Exception(err) {}
 
-   Lookup_Error(const std::string& type,
-                const std::string& algo,
-                const std::string& provider) :
-      Exception("Unavailable " + type + " " + algo +
-                (provider.empty() ? std::string("") : (" for provider " + provider)))
-      {}
+      Lookup_Error(const std::string& type,
+                   const std::string& algo,
+                   const std::string& provider) :
+         Exception("Unavailable " + type + " " + algo +
+                   (provider.empty() ? std::string("") : (" for provider " + provider)))
+         {}
    };
 
 /**
 * Internal_Error Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Internal_Error : public Exception
+class BOTAN_PUBLIC_API(2,0) Internal_Error : public Exception
    {
-   explicit Internal_Error(const std::string& err) :
-      Exception("Internal error: " + err)
-      {}
+   public:
+      explicit Internal_Error(const std::string& err) :
+         Exception("Internal error: " + err)
+         {}
    };
 
 /**
 * Invalid_Key_Length Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Invalid_Key_Length final : public Invalid_Argument
+class BOTAN_PUBLIC_API(2,0) Invalid_Key_Length final : public Invalid_Argument
    {
-   Invalid_Key_Length(const std::string& name, size_t length) :
-      Invalid_Argument(name + " cannot accept a key of length " +
-                       std::to_string(length))
-      {}
+   public:
+      Invalid_Key_Length(const std::string& name, size_t length) :
+         Invalid_Argument(name + " cannot accept a key of length " +
+                          std::to_string(length))
+         {}
    };
 
 /**
 * Invalid_IV_Length Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Invalid_IV_Length final : public Invalid_Argument
+class BOTAN_PUBLIC_API(2,0) Invalid_IV_Length final : public Invalid_Argument
    {
-   Invalid_IV_Length(const std::string& mode, size_t bad_len) :
-      Invalid_Argument("IV length " + std::to_string(bad_len) +
-                       " is invalid for " + mode)
-      {}
+   public:
+      Invalid_IV_Length(const std::string& mode, size_t bad_len) :
+         Invalid_Argument("IV length " + std::to_string(bad_len) +
+                          " is invalid for " + mode)
+         {}
    };
 
 /**
 * PRNG_Unseeded Exception
 */
-struct BOTAN_PUBLIC_API(2,0) PRNG_Unseeded final : public Invalid_State
+class BOTAN_PUBLIC_API(2,0) PRNG_Unseeded final : public Invalid_State
    {
-   explicit PRNG_Unseeded(const std::string& algo) :
-      Invalid_State("PRNG not seeded: " + algo)
-      {}
+   public:
+      explicit PRNG_Unseeded(const std::string& algo) :
+         Invalid_State("PRNG not seeded: " + algo)
+         {}
    };
 
 /**
 * Policy_Violation Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Policy_Violation final : public Invalid_State
+class BOTAN_PUBLIC_API(2,0) Policy_Violation final : public Invalid_State
    {
-   explicit Policy_Violation(const std::string& err) :
-      Invalid_State("Policy violation: " + err)
-      {}
+   public:
+      explicit Policy_Violation(const std::string& err) :
+         Invalid_State("Policy violation: " + err)
+         {}
    };
 
 /**
 * Algorithm_Not_Found Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Algorithm_Not_Found final : public Lookup_Error
+class BOTAN_PUBLIC_API(2,0) Algorithm_Not_Found final : public Lookup_Error
    {
-   explicit Algorithm_Not_Found(const std::string& name) :
-      Lookup_Error("Could not find any algorithm named \"" + name + "\"")
-      {}
+   public:
+      explicit Algorithm_Not_Found(const std::string& name) :
+         Lookup_Error("Could not find any algorithm named \"" + name + "\"")
+         {}
    };
 
 /**
 * No_Provider_Found Exception
 */
-struct BOTAN_PUBLIC_API(2,0) No_Provider_Found final : public Exception
+class BOTAN_PUBLIC_API(2,0) No_Provider_Found final : public Exception
    {
-   explicit No_Provider_Found(const std::string& name) :
-      Exception("Could not find any provider for algorithm named \"" + name + "\"")
-      {}
+   public:
+      explicit No_Provider_Found(const std::string& name) :
+         Exception("Could not find any provider for algorithm named \"" + name + "\"")
+         {}
    };
 
 /**
 * Provider_Not_Found is thrown when a specific provider was requested
 * but that provider is not available.
 */
-struct BOTAN_PUBLIC_API(2,0) Provider_Not_Found final : public Lookup_Error
+class BOTAN_PUBLIC_API(2,0) Provider_Not_Found final : public Lookup_Error
    {
-   Provider_Not_Found(const std::string& algo, const std::string& provider) :
-      Lookup_Error("Could not find provider '" + provider + "' for " + algo) {}
+   public:
+      Provider_Not_Found(const std::string& algo, const std::string& provider) :
+         Lookup_Error("Could not find provider '" + provider + "' for " + algo) {}
    };
 
 /**
 * Invalid_Algorithm_Name Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Invalid_Algorithm_Name final : public Invalid_Argument
+class BOTAN_PUBLIC_API(2,0) Invalid_Algorithm_Name final : public Invalid_Argument
    {
-   explicit Invalid_Algorithm_Name(const std::string& name):
-      Invalid_Argument("Invalid algorithm name: " + name)
-      {}
+   public:
+      explicit Invalid_Algorithm_Name(const std::string& name):
+         Invalid_Argument("Invalid algorithm name: " + name)
+         {}
    };
 
 /**
 * Encoding_Error Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Encoding_Error final : public Invalid_Argument
+class BOTAN_PUBLIC_API(2,0) Encoding_Error final : public Invalid_Argument
    {
-   explicit Encoding_Error(const std::string& name) :
-      Invalid_Argument("Encoding error: " + name) {}
+   public:
+      explicit Encoding_Error(const std::string& name) :
+         Invalid_Argument("Encoding error: " + name) {}
    };
 
 /**
 * Decoding_Error Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Decoding_Error : public Invalid_Argument
+class BOTAN_PUBLIC_API(2,0) Decoding_Error : public Invalid_Argument
    {
-   explicit Decoding_Error(const std::string& name) :
-      Invalid_Argument("Decoding error: " + name) {}
+   public:
+      explicit Decoding_Error(const std::string& name) :
+         Invalid_Argument("Decoding error: " + name) {}
    };
 
 /**
 * Integrity_Failure Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Integrity_Failure final : public Exception
+class BOTAN_PUBLIC_API(2,0) Integrity_Failure final : public Exception
    {
-   explicit Integrity_Failure(const std::string& msg) :
-      Exception("Integrity failure: " + msg) {}
+   public:
+      explicit Integrity_Failure(const std::string& msg) :
+         Exception("Integrity failure: " + msg) {}
    };
 
 /**
 * Invalid_OID Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Invalid_OID final : public Decoding_Error
+class BOTAN_PUBLIC_API(2,0) Invalid_OID final : public Decoding_Error
    {
-   explicit Invalid_OID(const std::string& oid) :
-      Decoding_Error("Invalid ASN.1 OID: " + oid) {}
+   public:
+      explicit Invalid_OID(const std::string& oid) :
+         Decoding_Error("Invalid ASN.1 OID: " + oid) {}
    };
 
 /**
 * Stream_IO_Error Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Stream_IO_Error final : public Exception
+class BOTAN_PUBLIC_API(2,0) Stream_IO_Error final : public Exception
    {
-   explicit Stream_IO_Error(const std::string& err) :
-      Exception("I/O error: " + err)
-      {}
+   public:
+      explicit Stream_IO_Error(const std::string& err) :
+         Exception("I/O error: " + err)
+         {}
    };
 
 /**
 * No_Filesystem_Access Exception
 */
-struct BOTAN_PUBLIC_API(2,0) No_Filesystem_Access final : public Exception
+class BOTAN_PUBLIC_API(2,0) No_Filesystem_Access final : public Exception
    {
-   No_Filesystem_Access() : Exception("No filesystem access enabled.") {}
+   public:
+      No_Filesystem_Access() : Exception("No filesystem access enabled.") {}
    };
 
 /**
 * Self Test Failure Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Self_Test_Failure final : public Internal_Error
+class BOTAN_PUBLIC_API(2,0) Self_Test_Failure final : public Internal_Error
    {
-   explicit Self_Test_Failure(const std::string& err) :
-      Internal_Error("Self test failed: " + err)
-      {}
+   public:
+      explicit Self_Test_Failure(const std::string& err) :
+         Internal_Error("Self test failed: " + err)
+         {}
    };
 
 /**
 * Not Implemented Exception
 */
-struct BOTAN_PUBLIC_API(2,0) Not_Implemented final : public Exception
+class BOTAN_PUBLIC_API(2,0) Not_Implemented final : public Exception
    {
-   explicit Not_Implemented(const std::string& err) :
-      Exception("Not implemented", err)
-      {}
+   public:
+      explicit Not_Implemented(const std::string& err) :
+         Exception("Not implemented", err)
+         {}
    };
 
 }
diff --git a/src/lib/utils/http_util/http_util.h b/src/lib/utils/http_util/http_util.h
index aa8e1cbc0..528a4fae8 100644
--- a/src/lib/utils/http_util/http_util.h
+++ b/src/lib/utils/http_util/http_util.h
@@ -19,7 +19,7 @@ namespace Botan {
 
 namespace HTTP {
 
-struct Response
+class Response
    {
    public:
       Response() : m_status_code(0), m_status_message("Uninitialized") {}
@@ -56,11 +56,12 @@ struct Response
 /**
 * HTTP_Error Exception
 */
-struct BOTAN_PUBLIC_API(2,0) HTTP_Error final : public Exception
+class BOTAN_PUBLIC_API(2,0) HTTP_Error final : public Exception
    {
-   explicit HTTP_Error(const std::string& msg) :
-      Exception("HTTP error " + msg)
-      {}
+   public:
+      explicit HTTP_Error(const std::string& msg) :
+         Exception("HTTP error " + msg)
+         {}
    };
 
 BOTAN_PUBLIC_API(2,0) std::ostream& operator<<(std::ostream& o, const Response& resp);