#include #include #include /* Have you ever wonder, about how many bytes it takes to have yourself a certain type of variable? well I did, so here's a little thing I did in attempt to try to understand it. Hope this helps in understanding basic data types, and the number of bytes required to allocate a variable of a certain type. Some types may include data ranges (integers only). ***************** Source ***************** https://msdn.microsoft.com/en-us/library/s3f49ktz.aspx https://en.m.wikipedia.org/wiki/C_data_types http://www.cplusplus.com/reference/cstdio/printf/ © 2017 SoloLearn Community */ /* function printInfo Description: Prints type information, optionally range Parameters: string Type name size_t Size of a certain type int Options string Type name alias (common) string Format Specifier (for printf) Return value: None (void) */ // Options for printInfo enum TYPEINFO_FLAGS { TI_BRIEF = 0, TI_UNSIGNED = 1, TI_SHOWRANGE = 2 }; void printInfo( const std::string& type_name, const size_t type_size, const int flags = TI_BRIEF, const std::string& type_alias = "", const std::string& format_spec = "") { int bitz = (int)(type_size * 8); // Basic if(flags & TI_UNSIGNED) { std::cout << "unsigned " << type_name; } else { std::cout << type_name; } std::cout << "\n Size: " << type_size << ((type_size > 1) ? " bytes (" : " byte (") << bitz << " bits)"; if(flags & TI_SHOWRANGE) { if(flags & TI_UNSIGNED) { unsigned long long ub {(unsigned long long) pow(2.0, bitz) - 1}; std::cout << "\n Range: (0 to " << ub << ")"; } else { --bitz; long long lb {(long long) pow(-2.0, bitz)}, ub {(long long) pow(2.0, bitz) - 1}; std::cout << "\n Range: (" << lb << " to " << ub << ")"; } } // Alias if(type_alias.size()) std::cout << "\n Equivalent: " << type_alias; // Format Specifier if(format_spec.size()) std::cout << "\n Format Specifier:\n" << format_spec; std::cout << "\n" << std::string(35, '+') << "\n\n"; } // Main procedure int main() { std::string typeName; std::cout << "Primitive types and amount of memory reqired (in bytes) to allocate an instance of the type."; std::cout << "\n\nNOTE: Data ranges are shown for integer types only.\n"; std::cout << std::string(35, '+') << "\n\n"; int utsr {TI_UNSIGNED | TI_SHOWRANGE}, sr {TI_SHOWRANGE}; // bool printInfo ("bool", sizeof (bool)); // char (signed & unsigned) typeName = "char"; printInfo (typeName, sizeof (char), sr, "int8_t", "- %c\n- %hhi (numeric output)"); printInfo (typeName, sizeof (unsigned char), utsr, "uint8_t", "- %c\n- %hhu (numeric output)"); // short (signed & unsigned) typeName = "short (int)"; printInfo (typeName, sizeof (short), sr, "int16_t", "- %hi"); printInfo (typeName, sizeof (unsigned short), utsr, "uint16_t", "- %hu"); // int (signed & unsigned) typeName = "int"; printInfo (typeName, sizeof (int), sr, "int32_t , signed", "- %i or %d"); printInfo (typeName, sizeof (unsigned int), utsr, "uint32_t , unsigned", "- %u"); // long (signed & unsigned) typeName= "long (int)"; printInfo (typeName, sizeof (long), sr, "", "- %li"); printInfo (typeName, sizeof (unsigned long), utsr, "", "- %lu"); // long long (signed & unsigned) typeName = "long long (int)"; printInfo (typeName, sizeof (long long), sr, "int64_t", "- %lli"); printInfo (typeName, sizeof (unsigned long long), utsr, "uint64_t", "- %llu"); // float, double and long double std::string fmtSpc = "- %a %A (Hexadecimal Format)\n- %e %E (Scientific Format)\n- %f %F (Decimal Format)\n- %g %G (Short form of %e %E or %f %F)"; printInfo ("float", sizeof (float),TI_BRIEF, "", fmtSpc); printInfo ("double", sizeof (double), TI_BRIEF, "", fmtSpc); printInfo ("long double ", sizeof (long double), TI_BRIEF, "", "- %La %LA\n- %Le %LE\n- %Lf %LF\n- %Lg %LG"); return 0; }