Safe Printing (ns_print)

In standard C, the printf function is inherently unsafe because it parses format strings (like %d or %s) at runtime. If the format string doesn’t perfectly match the variables you pass to it, the compiler might not catch it, leading to garbled output or severe security vulnerabilities.

NextStd replaces printf with two type-safe macros:

• ns_print(val): Prints the value to the standard output without a newline.
• ns_println(val): Prints the value and automatically appends a newline (\n).

Basic Usage

You never have to memorize format specifiers again. Simply pass your variable or literal directly into the macro, and NextStd will figure out how to print it.

#include <nextstd/ns.h>
#include <stdbool.h>

int main() {
    int age = 42;
    double pi = 3.14159;
    bool is_active = true;

    // Printing strings directly
    ns_println("--- User Profile ---");

    // Printing integers
    ns_print("Age: ");
    ns_println(age);

    // Printing floating-point numbers
    ns_print("Pi approximation: ");
    ns_println(pi);

    // Printing booleans (automatically formats as "true" or "false")
    ns_print("Account Active: ");
    ns_println(is_active);

    return 0;
}

How It Works Under the Hood

If C doesn’t support function overloading like C++ or Rust, how does ns_println know what type of data you are passing to it?

NextStd leverages a feature introduced in the C11 standard called _Generic selections. Think of it as a switch statement that evaluates data types at compile time rather than values at runtime.

When you call ns_print(val), the C preprocessor expands it into something like this:

// Simplified representation of the NextStd printing macro
#define ns_print(X) _Generic((X), \
    int: ns_print_int, \
    double: ns_print_double, \
    bool: ns_print_bool, \
    char*: ns_print_str, \
    const char*: ns_print_str \
)(X)

The Safety Guarantee

Because this evaluation happens strictly at compile time:

1. Zero Runtime Overhead: There is no format string to parse while your program is running. It is as fast as calling the specific print function directly.
2. Compile-Time Errors: If you try to pass a data type that NextStd doesn’t know how to print yet (like a raw struct or a multidimensional array), the compilation will fail immediately. It is impossible to accidentally trigger undefined behavior.