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#pragma once

static inline int _constexpr_assert_failure(const char *msg)
{
	// we do 2 things that the compiler will refuse to execute at compile-time
	// (and therefore trigger a compilation error):
	// - define a local static variable
	// - declare the method as non constexpr
	static int i = 0;
	return i;
}

/**
 * Assertion that fails compilation if used in a constexpr context (that is executed at
 * compile-time).
 *
 * Important: you need to ensure the code is executed at compile-time, e.g. by
 * assigning the returned value of a constexpr method (where the assert is used)
 * to a variable marked as constexpr. Otherwise the compiler might silently move
 * execution to runtime.
 *
 * If executed at runtime, it has no effect other than slight runtime overhead.
 */
#define constexpr_assert(expr, msg) if (!(expr)) { _constexpr_assert_failure(msg); }


