// Standalone teaching example, not Trace source or a product qualification.
// Requirement: contain at least one character other than ASCII space U+0020.
// This demonstrates a deliberately incomplete length-only implementation.
#include <iostream>
#include <string_view>

bool valid_name(std::string_view value) { return !value.empty(); }

int main() {
    struct Case { const char* label; std::string_view input; bool required; };
    constexpr Case cases[] = {
        {"ordinary", "example", true},
        {"empty", "", false},
        {"three ASCII spaces", "   ", false}
    };
    int mismatches = 0;
    std::cout << std::boolalpha;
    for (const auto& item : cases) {
        const bool observed = valid_name(item.input);
        std::cout << item.label << ": observed=" << observed
                  << ", required=" << item.required << '\n';
        if (observed != item.required) ++mismatches;
    }
    std::cout << "Requirement mismatches: " << mismatches << " of 3\n";
    // Success means the teaching example reproduced its one expected defect.
    return mismatches == 1 ? 0 : 1;
}