commit f95c5aeddbde6c7753efdf256f72b8bf935bfd59
Author: William Dillon <wmdillon@me.com>
Date:   Sun Nov 30 17:56:18 2025 -0500

    first commit

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..af41116
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,7 @@
+CXXFLAGS:=-std=c++23 -Wall -Wextra -pthread -g
+
+gostrings_test: gostrings.hpp
+	$(CXX) $(CXXFLAGS) -o gostrings_test gostrings_test.cpp -lpthread -lgtest
+
+clean:
+	rm -f gostrings_test
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..31f7c8f
--- /dev/null
+++ b/README.md
@@ -0,0 +1,15 @@
+# unimplemented functions:
+* func Clone(s string) string
+* func EqualFold(s, t string) bool
+* func FieldsFuncSeq(s string, f func(rune) bool) iter.Seq[string]
+* func FieldsSeq(s string) iter.Seq[string]
+* func Lines(s string) iter.Seq[string]
+* func Map(mapping func(rune) rune, s string) string
+* func SplitAfterSeq(s, sep string) iter.Seq[string]
+* func SplitSeq(s, sep string) iter.Seq[string]
+* func Title(s string) stringdeprecated
+* func ToLowerSpecial(c unicode.SpecialCase, s string) string
+* func ToTitle(s string) string
+* func ToTitleSpecial(c unicode.SpecialCase, s string) string
+* func ToUpperSpecial(c unicode.SpecialCase, s string) string
+* func ToValidUTF8(s, replacement string) string
\ No newline at end of file
diff --git a/gostrings.hpp b/gostrings.hpp
new file mode 100644
index 0000000..909db66
--- /dev/null
+++ b/gostrings.hpp
@@ -0,0 +1,347 @@
+#ifndef __GOSTRINGS_HPP__
+#define __GOSTRINGS_HPP__
+
+#include <string>
+#include <vector>
+
+namespace gostrings {
+
+inline int Compare(const std::string &a, const std::string &b) {
+    if (a == b) return 0;
+    return (a < b) ? -1 : 1;
+}
+
+inline bool Contains(const std::string &s, const std::string &substr) {
+    return s.find(substr) != std::string::npos;
+}
+
+inline bool ContainsAny(const std::string &s, const std::string &chars) {
+    return s.find_first_of(chars) != std::string::npos;
+}
+
+inline bool ContainsFunc(const std::string &s, bool (*f)(char)) {
+    for (char c : s) {
+        if (f(c)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+inline int Count(const std::string &s, const std::string &substr) {
+    if (substr.empty()) {
+        return static_cast<int>(s.size()) + 1;
+    }
+    int count = 0;
+    size_t pos = 0;
+    while ((pos = s.find(substr, pos)) != std::string::npos) {
+        ++count;
+        pos += substr.length();
+    }
+    return count;
+}
+
+struct CutPrefixResult {
+    std::string after;
+    bool found;
+};
+
+struct CutSuffixResult {
+    std::string before;
+    bool found;
+};
+
+struct CutResult {
+    CutPrefixResult prefix;
+    CutSuffixResult suffix;
+    inline bool found() const {
+        return prefix.found && suffix.found;
+    }
+};
+
+inline CutResult Cut(const std::string &s, const std::string &sep) {
+    size_t pos = s.find(sep);
+    if (pos == std::string::npos) {
+        return {{"", false}, {"", false}};
+    }
+    return { {s.substr(pos + sep.length()), true}, {s.substr(0, pos), true} };
+}
+
+inline CutPrefixResult CutPrefix(const std::string &s, const std::string &prefix) {
+    if (s.substr(0, prefix.length()) == prefix) {
+        return {s.substr(prefix.length()), true};
+    }
+    return {"", false};
+}
+
+inline CutSuffixResult CutSuffix(const std::string &s, const std::string &suffix) {
+    if (s.length() >= suffix.length() &&
+        s.substr(s.length() - suffix.length()) == suffix) {
+        return {s.substr(0, s.length() - suffix.length()), true};
+    }
+    return {"", false};
+}
+
+inline std::vector<std::string> Fields(const std::string &s) {
+    std::vector<std::string> result;
+    size_t start = s.find_first_not_of(" \t\n\r\f\v");
+    while (start != std::string::npos) {
+        size_t end = s.find_first_of(" \t\n\r\f\v", start);
+        result.push_back(s.substr(start, end - start));
+        start = s.find_first_not_of(" \t\n\r\f\v", end);
+    }
+    return result;
+}
+
+inline std::vector<std::string> FieldsFunc(const std::string &s, bool (*f)(char)) {
+    std::vector<std::string> result;
+    size_t start = 0;
+    while (start < s.length()) {
+        while (start < s.length() && f(s[start])) {
+            ++start;
+        }
+        if (start >= s.length()) break;
+        size_t end = start;
+        while (end < s.length() && !f(s[end])) {
+            ++end;
+        }
+        result.push_back(s.substr(start, end - start));
+        start = end;
+    }
+    return result;
+}
+
+inline bool HasPrefix(const std::string &s, const std::string &prefix) {
+    return s.substr(0, prefix.length()) == prefix;
+}
+
+inline bool HasSuffix(const std::string &s, const std::string &suffix) {
+    return s.length() >= suffix.length() &&
+           s.substr(s.length() - suffix.length()) == suffix;
+}
+
+inline size_t Index(const std::string &s, const std::string &substr) {
+    size_t pos = s.find(substr);
+    return (pos == std::string::npos) ? -1 : pos;
+}
+
+inline size_t IndexAny(const std::string &s, const std::string &chars) {
+    size_t pos = s.find_first_of(chars);
+    return (pos == std::string::npos) ? -1 : pos;
+}
+
+inline size_t IndexByte(const std::string &s, char c) {
+    size_t pos = s.find(c);
+    return (pos == std::string::npos) ? -1 : pos;
+}
+
+inline size_t IndexFunc(const std::string &s, bool (*f)(char)) {
+    for (size_t i = 0; i < s.length(); ++i) {
+        if (f(s[i])) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+inline std::string Join(const std::vector<std::string> &elems, const std::string &sep) {
+    std::string result;
+    for (size_t i = 0; i < elems.size(); ++i) {
+        result += elems[i];
+        if (i < elems.size() - 1) {
+            result += sep;
+        }
+    }
+    return result;
+}
+
+inline size_t LastIndex(const std::string &s, const std::string &substr) {
+    size_t pos = s.rfind(substr);
+    return (pos == std::string::npos) ? -1 : pos;
+}
+
+inline size_t LastIndexAny(const std::string &s, const std::string &chars) {
+    size_t pos = s.find_last_of(chars);
+    return (pos == std::string::npos) ? -1 : pos;
+}
+
+inline size_t LastIndexByte(const std::string &s, char c) {
+    size_t pos = s.rfind(c);
+    return (pos == std::string::npos) ? -1 : pos;
+}
+
+inline size_t LastIndexFunc(const std::string &s, bool (*f)(char)) {
+    for (size_t i = s.length(); i-- > 0;) {
+        if (f(s[i])) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+inline std::string Repeat(const std::string &s, int count) {
+    if (count <= 0) return "";
+    std::string result;
+    for (int i = 0; i < count; ++i) {
+        result += s;
+    }
+    return result;
+}
+
+inline std::string Replace(const std::string &s, const std::string &old, const std::string &newstr, int n) {
+    std::string result = s;
+    size_t pos = 0;
+    int count = 0;
+    while ((pos = result.find(old, pos)) != std::string::npos) {
+        if (n != -1 && count >= n) break;
+        result.replace(pos, old.length(), newstr);
+        pos += newstr.length();
+        ++count;
+    }
+    return result;
+}
+
+inline std::string ReplaceAll(const std::string &s, const std::string &old, const std::string &newstr) {
+    return Replace(s, old, newstr, -1);
+}
+
+inline std::vector<std::string> Split(const std::string &s, const std::string &sep) {
+    std::vector<std::string> result;
+    size_t start = 0;
+    size_t end;
+    while ((end = s.find(sep, start)) != std::string::npos) {
+        result.push_back(s.substr(start, end - start));
+        start = end + sep.length();
+    }
+    result.push_back(s.substr(start));
+    return result;
+}
+
+inline std::vector<std::string> SplitAfter(const std::string &s, const std::string &sep) {
+    std::vector<std::string> result;
+    size_t start = 0;
+    size_t end;
+    while ((end = s.find(sep, start)) != std::string::npos) {
+        result.push_back(s.substr(start, end + sep.length() - start));
+        start = end + sep.length();
+    }
+    result.push_back(s.substr(start));
+    return result;
+}
+
+inline std::vector<std::string> SplitAfterN(const std::string &s, const std::string &sep, int n) {
+    std::vector<std::string> result;
+    size_t start = 0;
+    size_t end;
+    int count = 0;
+    while (count < n - 1 && (end = s.find(sep, start)) != std::string::npos) {
+        result.push_back(s.substr(start, end + sep.length() - start));
+        start = end + sep.length();
+        ++count;
+    }
+    result.push_back(s.substr(start));
+    return result;
+}
+
+inline std::vector<std::string> SplitN(const std::string &s, const std::string &sep, int n) {
+    std::vector<std::string> result;
+    size_t start = 0;
+    size_t end;
+    int count = 0;
+    while (count < n - 1 && (end = s.find(sep, start)) != std::string::npos) {
+        result.push_back(s.substr(start, end - start));
+        start = end + sep.length();
+        ++count;
+    }
+    result.push_back(s.substr(start));
+    return result;
+}
+
+inline std::string ToLower(const std::string &s) {
+    std::string result = s;
+    for (char &c : result) {
+        c = static_cast<char>(tolower(static_cast<unsigned char>(c)));
+    }
+    return result;
+}
+
+inline std::string ToUpper(const std::string &s) {
+    std::string result = s;
+    for (char &c : result) {
+        c = static_cast<char>(toupper(static_cast<unsigned char>(c)));
+    }
+    return result;
+}
+
+inline std::string Trim(const std::string &s, const std::string &cutset) {
+    size_t start = s.find_first_not_of(cutset);
+    if (start == std::string::npos) return "";
+    size_t end = s.find_last_not_of(cutset);
+    return s.substr(start, end - start + 1);
+}
+
+inline std::string TrimFunc(const std::string &s, bool (*f)(char)) {
+    size_t start = 0;
+    while (start < s.length() && f(s[start])) {
+        ++start;
+    }
+    if (start == s.length()) return "";
+    size_t end = s.length() - 1;
+    while (end > start && f(s[end])) {
+        --end;
+    }
+    return s.substr(start, end - start + 1);
+}
+
+inline std::string TrimLeft(const std::string &s, const std::string &cutset) {
+    size_t start = s.find_first_not_of(cutset);
+    if (start == std::string::npos) return "";
+    return s.substr(start);
+}
+
+inline std::string TrimLeftFunc(const std::string &s, bool (*f)(char)) {
+    size_t start = 0;
+    while (start < s.length() && f(s[start])) {
+        ++start;
+    }
+    return s.substr(start);
+}
+
+inline std::string TrimPrefix(const std::string &s, const std::string &prefix) {
+    if (s.substr(0, prefix.length()) == prefix) {
+        return s.substr(prefix.length());
+    }
+    return s;
+}
+
+inline std::string TrimRight(const std::string &s, const std::string &cutset) {
+    size_t end = s.find_last_not_of(cutset);
+    if (end == std::string::npos) return "";
+    return s.substr(0, end + 1);
+}
+
+inline std::string TrimRightFunc(const std::string &s, bool (*f)(char)) {
+    size_t end = s.length();
+    while (end > 0 && f(s[end - 1])) {
+        --end;
+    }
+    return s.substr(0, end);
+}
+
+inline std::string TrimSpace(const std::string &s) {
+    return Trim(s, " \t\n\r\f\v");
+}
+
+inline std::string TrimSuffix(const std::string &s, const std::string &suffix) {
+    if (s.length() >= suffix.length() &&
+        s.substr(s.length() - suffix.length()) == suffix) {
+        return s.substr(0, s.length() - suffix.length());
+    }
+    return s;
+}
+
+} // namespace gostrings
+
+
+
+#endif // __GOSTRINGS_HPP__
\ No newline at end of file
diff --git a/gostrings_test.cpp b/gostrings_test.cpp
new file mode 100644
index 0000000..0ac6272
--- /dev/null
+++ b/gostrings_test.cpp
@@ -0,0 +1,246 @@
+#include "gostrings.hpp"
+#include <gtest/gtest.h>
+
+TEST(GoStringsTest, Compare) {
+    EXPECT_EQ(gostrings::Compare("apple", "apple"), 0);
+    EXPECT_EQ(gostrings::Compare("apple", "banana"), -1);
+    EXPECT_EQ(gostrings::Compare("banana", "apple"), 1);
+}
+
+TEST(GoStringsTest, Contains) {
+    EXPECT_TRUE(gostrings::Contains("hello world", "world"));
+    EXPECT_FALSE(gostrings::Contains("hello world", "mars"));
+}
+
+TEST(GoStringsTest, ContainsFunc) {
+    auto isVowel = [](char c) {
+        c = tolower(c);
+        return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';
+    };
+    EXPECT_TRUE(gostrings::ContainsFunc("hello", isVowel));
+    EXPECT_FALSE(gostrings::ContainsFunc("rhythm", isVowel));
+}
+
+TEST(GoStringsTest, Count) {
+    EXPECT_EQ(gostrings::Count("ababab", "ab"), 3);
+    EXPECT_EQ(gostrings::Count("aaaa", "aa"), 2);
+    EXPECT_EQ(gostrings::Count("hello", "world"), 0);
+    EXPECT_EQ(gostrings::Count("hello", ""), 6);
+}
+
+TEST(GoStringsTest, Cut) {
+    auto result = gostrings::Cut("hello world", " ");
+    EXPECT_TRUE(result.found());
+    EXPECT_EQ(result.prefix.after, "world");
+    EXPECT_EQ(result.suffix.before, "hello");
+
+    result = gostrings::Cut("helloworld", " ");
+    EXPECT_FALSE(result.found());
+}
+
+TEST(GoStringsTest, CutPrefix) {
+    auto result = gostrings::CutPrefix("hello world", "hello ");
+    EXPECT_TRUE(result.found);
+    EXPECT_EQ(result.after, "world");
+
+    result = gostrings::CutPrefix("hello world", "world ");
+    EXPECT_FALSE(result.found);
+
+}
+
+TEST(GoStringsTest, CutSuffix) {
+    auto result = gostrings::CutSuffix("hello world", " world");
+    EXPECT_TRUE(result.found);
+    EXPECT_EQ(result.before, "hello");
+
+    result = gostrings::CutSuffix("hello world", " hello");
+    EXPECT_FALSE(result.found);
+}
+
+TEST(GoStringsTest, Fields) {
+    auto result = gostrings::Fields("  hello   world  ");
+    ASSERT_EQ(result.size(), 2);
+    EXPECT_EQ(result[0], "hello");
+    EXPECT_EQ(result[1], "world");
+}
+
+TEST(GoStringsTest, FieldsFunc) {
+    auto isSpace = [](char c) {
+        return c == ' ' || c == '\t' || c == '\n';
+    };
+    auto result = gostrings::FieldsFunc("  hello\tworld\n", isSpace);
+    ASSERT_EQ(result.size(), 2);
+    EXPECT_EQ(result[0], "hello");
+    EXPECT_EQ(result[1], "world");
+}
+
+TEST(GoStringsTest, HasPrefix) {
+    EXPECT_TRUE(gostrings::HasPrefix("hello world", "hello"));
+    EXPECT_FALSE(gostrings::HasPrefix("hello world", "world"));
+}
+
+TEST(GoStringsTest, Index) {
+    EXPECT_EQ(gostrings::Index("hello world", "world"), 6);
+    EXPECT_EQ(gostrings::Index("hello world", "mars"), -1);
+}
+
+TEST(GoStringsTest, IndexAny) {
+    EXPECT_EQ(gostrings::IndexAny("hello world", "aeiou"), 1);
+    EXPECT_EQ(gostrings::IndexAny("rhythm", "aeiou"), -1);
+}
+
+TEST(GoStringsTest, IndexByte) {
+    EXPECT_EQ(gostrings::IndexByte("hello world", 'o'), 4);
+    EXPECT_EQ(gostrings::IndexByte("hello world", 'z'), -1);
+}
+
+TEST(GoStringsTest, IndexFunc) {
+    auto isVowel = [](char c) {
+        c = tolower(c);
+        return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';
+    };
+    EXPECT_EQ(gostrings::IndexFunc("hello", isVowel), 1);
+    EXPECT_EQ(gostrings::IndexFunc("rhythm", isVowel), -1);
+}
+
+TEST(GoStringsTest, Join) {
+    std::vector<std::string> elems = {"hello", "world"};
+    EXPECT_EQ(gostrings::Join(elems, " "), "hello world");
+}
+
+TEST(GoStringsTest, LastIndex) {
+    EXPECT_EQ(gostrings::LastIndex("ababcabc", "abc"), 5);
+    EXPECT_EQ(gostrings::LastIndex("hello world", "mars"), -1);
+}
+
+TEST(GoStringsTest, LastIndexAny) {
+    EXPECT_EQ(gostrings::LastIndexAny("hello world", "aeiou"), 7);
+    EXPECT_EQ(gostrings::LastIndexAny("rhythm", "aeiou"), -1);
+}
+
+TEST(GoStringsTest, LastIndexByte) {
+    EXPECT_EQ(gostrings::LastIndexByte("hello world", 'o'), 7);
+    EXPECT_EQ(gostrings::LastIndexByte("hello world", 'z'), -1);
+}
+
+TEST(GoStringsTest, LastIndexFunc) {
+    auto isVowel = [](char c) {
+        c = tolower(c);
+        return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';
+    };
+    EXPECT_EQ(gostrings::LastIndexFunc("hello", isVowel), 4);
+    EXPECT_EQ(gostrings::LastIndexFunc("rhythm", isVowel), -1);
+}
+
+TEST(GoStringsTest, Repeat) {
+    EXPECT_EQ(gostrings::Repeat("ab", 3), "ababab");
+    EXPECT_EQ(gostrings::Repeat("xyz", 0), "");
+}
+
+TEST(GoStringsTest, Replace) {
+    EXPECT_EQ(gostrings::Replace("ababab", "ab", "xy", 2), "xyxyab");
+    EXPECT_EQ(gostrings::Replace("hello world", "world", "mars", -1), "hello mars");
+}
+
+TEST(GoStringsTest, ReplaceAll) {
+    EXPECT_EQ(gostrings::ReplaceAll("ababab", "ab", "xy"), "xyxyxy");
+    EXPECT_EQ(gostrings::ReplaceAll("hello world", "world", "mars"), "hello mars");
+}
+
+TEST(GoStringsTest, Split) {
+    auto result = gostrings::Split("a,b,c", ",");
+    ASSERT_EQ(result.size(), 3);
+    EXPECT_EQ(result[0], "a");
+    EXPECT_EQ(result[1], "b");
+    EXPECT_EQ(result[2], "c");
+}
+
+TEST(GoStringsTest, SplitAfter) {
+    auto result = gostrings::SplitAfter("a,b,c", ",");
+    ASSERT_EQ(result.size(), 3);
+    EXPECT_EQ(result[0], "a,");
+    EXPECT_EQ(result[1], "b,");
+    EXPECT_EQ(result[2], "c");
+}
+
+TEST(GoStringsTest, SplitAfterN) {
+    auto result = gostrings::SplitAfterN("a,b,c,d", ",", 3);
+    ASSERT_EQ(result.size(), 3);
+    EXPECT_EQ(result[0], "a,");
+    EXPECT_EQ(result[1], "b,");
+    EXPECT_EQ(result[2], "c,d");
+}
+
+TEST(GoStringsTest, SplitN) {
+    auto result = gostrings::SplitN("a,b,c,d", ",", 3);
+    ASSERT_EQ(result.size(), 3);
+    EXPECT_EQ(result[0], "a");
+    EXPECT_EQ(result[1], "b");
+    EXPECT_EQ(result[2], "c,d");
+}
+
+TEST(GoStringsTest, ToLower) {
+    EXPECT_EQ(gostrings::ToLower("HeLLo WoRLD"), "hello world");
+}
+
+TEST(GoStringsTest, ToUpper) {
+    EXPECT_EQ(gostrings::ToUpper("HeLLo WoRLD"), "HELLO WORLD");
+}
+
+TEST(GoStringsTest, Trim) {
+    EXPECT_EQ(gostrings::Trim("  hello world  ", " "), "hello world");
+}
+
+TEST(GoStringsTest, TrimFunc) {
+    auto isSpace = [](char c) {
+        return c == ' ' || c == '\t' || c == '\n';
+    };
+    EXPECT_EQ(gostrings::TrimFunc("  \thello world\n  ", isSpace), "hello world");
+}
+
+TEST(GoStringsTest, TrimLeft) {
+    EXPECT_EQ(gostrings::TrimLeft("  hello world  ", " "), "hello world  ");
+}
+
+TEST(GoStringsTest, TrimLeftFunc) {
+    auto isSpace = [](char c) {
+        return c == ' ' || c == '\t' || c == '\n';
+    };
+    EXPECT_EQ(gostrings::TrimLeftFunc("  \thello world\n  ", isSpace), "hello world\n  ");
+}
+
+TEST(GoStringsTest, TrimPrefix) {
+    auto result = gostrings::TrimPrefix("hello world", "hello ");
+    EXPECT_EQ(result, "world");
+
+    result = gostrings::TrimPrefix("hello world", "world ");
+    EXPECT_EQ(result, "hello world");
+}
+
+TEST(GoStringsTest, TrimRight) {
+    EXPECT_EQ(gostrings::TrimRight("  hello world  ", " "), "  hello world");
+}
+
+TEST(GoStringsTest, TrimRightFunc) {
+    auto isSpace = [](char c) {
+        return c == ' ' || c == '\t' || c == '\n';
+    };
+    EXPECT_EQ(gostrings::TrimRightFunc("  \thello world\n  ", isSpace), "  \thello world");
+}
+
+TEST(GoStringsTest, TrimSpace) {
+    EXPECT_EQ(gostrings::TrimSpace("  \thello world\n  "), "hello world");
+}
+
+TEST(GoStringsTest, TrimSuffix) {
+    auto result = gostrings::TrimSuffix("hello world", " world");
+    EXPECT_EQ(result, "hello");
+
+    result = gostrings::TrimSuffix("hello world", " hello");
+    EXPECT_EQ(result, "hello world");
+}
+
+int main(int argc, char **argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}
\ No newline at end of file