text: #include <stan/util/io/starts_with.hpp>
  #include <gtest/gtest.h>
  #include <string>
  
  void expect_starts(const std::string& p, const std::string& s, bool cond) {
    EXPECT_EQ(cond, stan::io::starts_with(p, s));
  }
  
  TEST(Io, StartsWith) {
    expect_starts("", "", true);
    expect_starts("", "a", true);
    expect_starts("abc", "abc", true);
    expect_starts("abc", "abcd", true);
  
    expect_starts("a", "", false);
    expect_starts("abc", "ab", false);
  }
  