Char array to int avoiding dynamic memory allocation

[ms84coder]

Hi,

I realise that the topic of char to int has been covered quite extensively in a number of posts but I can't see anything which discusses the conversion of a char array to an int avoiding dynamic memory allocation. To put my question into context I'm looking to run my code on a microcontroller and I'm worried about dynamic memory allocation causing problems. I realise methods such as atoi don't provide any error detection - but to my knowledge it doesn't dynamically allocate memory.

uint8_t data_uint8[3] = { '1', '9', '1 };
const char* data_ptr = reinterpret_cast<char*>(data_uint8);
result = atoi(data_ptr); 

Conversion without dynamic memory allocation.

uint8_t data_uint8[3] = { '1', '9', '1 };
const char* data_ptr = reinterpret_cast<char*>(data_uint8);
std::string str = std::string(data_ptr, 3);
result = std::stoi(str); 

Conversion with dynamic memory allocation (string).

Is there a way of doing the conversion which avoids dynamic memory allocation? Or in this instance is it best to use an unsafe function such as atoi?

[mbozzi]

Consider std::from_chars
https://en.cppreference.com/w/cpp/utility/from_chars