need a help to find detailed documentation

I am learning to program C/C++ and I would like the information where to find , very detailed, infomation to increase my learning process. All information in this site I found in high level as I really had a kind of background. I appreciated if someone point me a link that could cover my gaps described below.

  • this statement :

#include <ESP8266WiFi.h> // where to find all functions and sub functions related, parameters and samples? I want to know if exists a good source, for any library

  • this statement :
    uint8_t buff[128] = { 0 }; // whats the maximum size that can be used? I try to increase to 25000 but it seems to crash on the execution (but compiling was ok)

  • this statement :
    size_t size = stream->available(); // more detail to show how to use stream and what does the operator " ->"

  • this statement :
    int c = stream->readBytes(buff, ((size > sizeof(buff)) ? sizeof(buff) : size));// more detail to show how to use stream and what does the operator " ->"

  • this statement :
    static int run_face_recognition(dl_matrix3du_t *image_matrix, box_array_t *net_boxes){
    dl_matrix3du_t *aligned_face = NULL; // what does * in this case

  • this statement :

void listDir(fs::FS &fs, const char * dirname, uint8_t levels){// what does * and :: in this case

  • this statement :
    esp_err_t err = esp_camera_init(&config); // what does &

thank you

Documentation for libraries can be found on the author/maintainers github and/or website. There is no centralized place for them, as any person can release a library. In some cases there are multiple versions of a library with the same name but different behavior. as people fork eachothers libraries (github is great, but it does promote proliferation of same named libraries)

& and * are standard c operators related to pointers, any c or c++ documentation will describe them.

Maximum size of an array is determined by ram and flash of the target device.

Edujtm:
I am learning to program C/C++ and I would like the information where to find , very detailed, infomation to increase my learning process.

I found this tutorial very helpful in learning C++:
http://www.cplusplus.com/doc/tutorial/program_structure/
Not all the information is going to be relevant to Arduino projects so you do need to be able to filter out the useful information. I would recommend first learning using the Arduino-specific information found in the Language Reference and Tutorials pages on this website. After that, you’ll have a good enough foundation to understand which parts of the cplusplus.com tutorial will be useful for expanding your understanding of C++ as it applies to Arduino projects.

Edujtm:
#include <ESP8266WiFi.h> // where to find all functions and sub functions related, parameters and samples? I want to know if exists a good source, for any library

The ESP8266WiFi library follows the API of the Arduino WiFi library, which is documented here:
https://www.arduino.cc/en/Reference/WiFi
It also has additional functions beyond those of the WiFi API, which are documented here:
https://arduino-esp8266.readthedocs.io/en/2.5.0/esp8266wifi/readme.html

It helps a lot thank all you!!