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Rewrite IPAddress without union #8829

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Rewrite IPAddress without union #8829

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46 changes: 23 additions & 23 deletions cores/esp32/IPAddress.cpp
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -20,62 +20,62 @@
#include <Arduino.h>
#include <IPAddress.h>
#include <Print.h>
#include <algorithm>

IPAddress::IPAddress()
{
_address.dword = 0;
}
// IPAddress::IPAddress()
// {
// _address.dword = 0;
// }

IPAddress::IPAddress(uint8_t first_octet, uint8_t second_octet, uint8_t third_octet, uint8_t fourth_octet)
{
_address.bytes[0] = first_octet;
_address.bytes[1] = second_octet;
_address.bytes[2] = third_octet;
_address.bytes[3] = fourth_octet;
}
: _address({first_octet,
second_octet,
third_octet,
fourth_octet})
{}

IPAddress::IPAddress(uint32_t address)
{
_address.dword = address;
uint32_t& addressRef = reinterpret_cast<uint32_t&>(_address.front());
addressRef = address;
}

IPAddress::IPAddress(const uint8_t *address)
{
memcpy(_address.bytes, address, sizeof(_address.bytes));
}
IPAddress::IPAddress(const uint8_t *address) : _address({address[0], address[1], address[2], address[3]})
{}

IPAddress& IPAddress::operator=(const uint8_t *address)
{
memcpy(_address.bytes, address, sizeof(_address.bytes));
std::copy(address, address + _address.size(), _address.begin());
return *this;
}

IPAddress& IPAddress::operator=(uint32_t address)
{
_address.dword = address;
uint32_t& addressRef = reinterpret_cast<uint32_t&>(_address.front());
addressRef = address;
return *this;
}

bool IPAddress::operator==(const uint8_t* addr) const
{
return memcmp(addr, _address.bytes, sizeof(_address.bytes)) == 0;
return std::equal(_address.begin(), _address.end(), addr);
}

size_t IPAddress::printTo(Print& p) const
{
size_t n = 0;
for(int i = 0; i < 3; i++) {
n += p.print(_address.bytes[i], DEC);
n += p.print(_address[i], DEC);
n += p.print('.');
}
n += p.print(_address.bytes[3], DEC);
n += p.print(_address[3], DEC);
return n;
}

String IPAddress::toString() const
{
char szRet[16];
sprintf(szRet,"%u.%u.%u.%u", _address.bytes[0], _address.bytes[1], _address.bytes[2], _address.bytes[3]);
sprintf(szRet,"%u.%u.%u.%u", _address[0], _address[1], _address[2], _address[3]);
return String(szRet);
}

Expand Down Expand Up @@ -103,7 +103,7 @@ bool IPAddress::fromString(const char *address)
// Too much dots (there must be 3 dots)
return false;
}
_address.bytes[dots++] = acc;
_address[dots++] = acc;
acc = 0;
}
else
Expand All @@ -117,7 +117,7 @@ bool IPAddress::fromString(const char *address)
// Too few dots (there must be 3 dots)
return false;
}
_address.bytes[3] = acc;
_address[3] = acc;
return true;
}

Expand Down
19 changes: 9 additions & 10 deletions cores/esp32/IPAddress.h
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Original file line number Diff line number Diff line change
Expand Up @@ -23,29 +23,27 @@
#include <stdint.h>
#include <WString.h>
#include <Printable.h>
#include <array>

// A class to make it easier to handle and pass around IP addresses

class IPAddress: public Printable
{
private:
union {
uint8_t bytes[4]; // IPv4 address
uint32_t dword;
} _address;
alignas(alignof(uint32_t)) std::array<uint8_t,4> _address{}; // IPv4 address
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@TD-er TD-er Nov 3, 2023 •
edited
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Does std::array initialize with a zero value?
You did remove the default constructor, so it must be set to zero here.

Edit:
Yep, the {} does indeed initialize all elements.
See: https://en.cppreference.com/w/cpp/container/array

I was a bit worried it might only initialize the array and not just its elements as that was indeed an issue with C++11 requiring double braces.


// Access the raw byte array containing the address. Because this returns a pointer
// to the internal structure rather than a copy of the address this function should only
// be used when you know that the usage of the returned uint8_t* will be transient and not
// stored.
uint8_t* raw_address()
{
return _address.bytes;
return _address.data();
}

public:
// Constructors
IPAddress();
IPAddress() = default;
IPAddress(uint8_t first_octet, uint8_t second_octet, uint8_t third_octet, uint8_t fourth_octet);
IPAddress(uint32_t address);
IPAddress(const uint8_t *address);
Expand All @@ -54,26 +52,27 @@ class IPAddress: public Printable
bool fromString(const char *address);
bool fromString(const String &address) { return fromString(address.c_str()); }


// Overloaded cast operator to allow IPAddress objects to be used where a pointer
// to a four-byte uint8_t array is expected
operator uint32_t() const
{
return _address.dword;
return reinterpret_cast<const uint32_t&>(_address.front());
}
bool operator==(const IPAddress& addr) const
{
return _address.dword == addr._address.dword;
return _address == addr._address;
}
bool operator==(const uint8_t* addr) const;

// Overloaded index operator to allow getting and setting individual octets of the address
uint8_t operator[](int index) const
{
return _address.bytes[index];
return _address[index];
}
uint8_t& operator[](int index)
{
return _address.bytes[index];
return _address[index];
}

// Overloaded copy operators to allow initialisation of IPAddress objects from other types
Expand Down