Datatypes C++ Module

struct Result

Structure to represent an SNMP result.

This structure holds the information retrieved from an SNMP operation, including the OID, index, type, and value of the retrieved data.

Public Types

using ConvertedValue = std::variant<int, uint32_t, uint64_t, double, std::string, std::vector<unsigned char>>

Public Functions

std::string _to_string() const

Converts the Result object to a string representation.

This method generates a human-readable string representation of the Result object, including all its members.

Returns:

A string representation of the Result object.

ConvertedValue _make_converted_value(std::string const &type, std::string const &value)

Factory function to obtain the appropriate ConvertedValue type based on an SNMP type string.

This function takes an SNMP type string and a value string, then attempts to convert the value into the corresponding C++ type. The converted value is stored in a ConvertedValue, which is a std::variant.

Parameters:
Returns:

ConvertedValue The value converted to the appropriate C++ type, wrapped in a std::variant.

void update_converted_value()

Updates the converted_value member by converting the current type and value.

This method recalculates and assigns the converted_value field using the current values of the type and value members. It utilizes the private helper function _make_converted_value to perform the conversion.

Typically called after type or value has changed to ensure converted_value is up-to-date.

Public Members

std::string oid = ""

Object Identifier (OID) of the retrieved data.

std::string index = ""

Index of the retrieved data (if applicable).

std::string type = ""

Data type of the retrieved value.

std::string value = ""

Actual value of the retrieved data.

ConvertedValue converted_value = ""

Converted value of the type,value data.

Result.converted_value Types and Results

This section outlines the possible C++ data types that result from the converted_value member of the Result struct. The conversion is based on the SNMP type string. The underlying C++ type is a std::variant that can hold one of the following types or an error string.

Numeric Types

These SNMP types are converted into their corresponding C++ numeric equivalents. The conversion logic is designed to extract numerical data from common SNMP output formats, such as "60000 milli-seconds" or "up(1)".

Integer / Integer32

  • SNMP Types: integer, integer32

  • C++ Type: int32_t (signed 32-bit integer)

  • Example Input: "42" -> 42

Gauge32 / Counter32 / TimeTicks

  • SNMP Types: gauge32, counter32, timeticks

  • C++ Type: uint32_t (unsigned 32-bit integer)

  • Example Input: "363647793" -> 363647793

Counter64

  • SNMP Types: counter64

  • C++ Type: uint64_t (unsigned 64-bit integer)

  • Example Input: "18446744073709551615" -> 18446744073709551615

Byte Vector Types

These types represent raw byte data and are converted into a vector of unsigned characters.

Hex-STRING

  • SNMP Type: hex-string

  • C++ Type: std::vector<unsigned char>

  • Description: Parses a space-separated string of hexadecimal bytes. Each byte must be 1 or 2 hex characters long.

  • Example Input: "80 00 1F 88 04 01 01" -> {0x80, 0x00, 0x1F, 0x88, 0x04, 0x01, 0x01}

  • Special Case: An empty or whitespace-only input string results in an empty vector.

OctetStr

  • SNMP Type: octetstr

  • C++ Type: std::vector<unsigned char>

  • Description: Converts the raw string value directly into a vector of its character bytes.

  • Example Input: "Hello" -> {'H', 'e', 'l', 'l', 'o'} or {0x48, 0x65, 0x6c, 0x6c, 0x6f}

String Types

For many SNMP types, the most useful representation is the original string itself. These types are passed through without conversion.

  • SNMP Types:

    • string

    • oid, objid, objidentity

    • ipaddress, network address

    • opaque

    • bitstring

    • nsapaddress

    • traptype, notiftype

    • objgroup, notifgroup, modid, agentcap, modcomp

    • null

    • other

  • C++ Type: std::string

  • Description: The original string value from the Result is returned as is.

  • Example Input: "1.3.6.1.2.1.1.1.0" -> "1.3.6.1.2.1.1.1.0"

Error and Fallback Conditions

If a conversion fails or the type is unknown, the converted_value will hold a std::string describing the issue.

Conversion Error

  • C++ Type: std::string

  • Description: Occurs when a numeric or hex conversion fails due to malformed input. The string will contain a descriptive error message.

  • Example: "Integer Conversion Error: std::invalid_argument"

  • Example: "Hex-STRING Conversion Error: Malformed hex part 'G0'"

Unknown Type

  • C++ Type: std::string

  • Description: If the SNMP type string does not match any of the known types listed above, a generic fallback message is returned.

  • Value: "Unknown Type Conversion"