add pre C++20 APIs that don't use span

CMakeLists.txt

@@ -44,6 +44,10 @@ if(USE_CUDA AND CMAKE_CUDA_COMPILER AND CMAKE_BUILD_TYPE STREQUAL "Debug")
   add_compile_definitions(_DEBUG=1)
 endif()
 
+if(MSVC)
+  add_compile_options(/Zc:__cplusplus)  # set updated value for __cplusplus macro instead of 199711L
+endif()
+
 message(STATUS "Adding source files")
 
 file(GLOB generator_srcs CONFIGURE_DEPENDS

benchmark/c/main.cpp

@@ -123,7 +123,9 @@ std::string GeneratePrompt(size_t num_prompt_tokens, const OgaModel& model, cons
   params->SetInputSequences(*base_prompt_sequences);
 
   auto output_sequences = model.Generate(*params);
-  return std::string{tokenizer.Decode(output_sequences->Get(0))};
+  const auto output_sequence_length = output_sequences->SequenceCount(0);
+  const auto* output_sequence_data = output_sequences->SequenceData(0);
+  return std::string{tokenizer.Decode(output_sequence_data, output_sequence_length)};
 }
 
 void RunBenchmark(const benchmark::Options& opts) {
@@ -148,7 +150,7 @@ void RunBenchmark(const benchmark::Options& opts) {
     tokenizer->Encode(prompt.c_str(), *prompt_sequences);
   }
 
-  const size_t num_prompt_tokens = prompt_sequences->Get(0).size();
+  const size_t num_prompt_tokens = prompt_sequences->SequenceCount(0);
   const size_t num_tokens = num_prompt_tokens + opts.num_tokens_to_generate;
 
   auto make_generator_params = [&] {
@@ -169,7 +171,9 @@ void RunBenchmark(const benchmark::Options& opts) {
     if (opts.verbose && i == 0) {
       // show prompt and output on first iteration
       std::cout << "Prompt:\n\t" << prompt << "\n";
-      auto output = tokenizer->Decode(output_sequences->Get(0));
+      const auto output_sequence_length = output_sequences->SequenceCount(0);
+      const auto* output_sequence_data = output_sequences->SequenceData(0);
+      const auto output = tokenizer->Decode(output_sequence_data, output_sequence_length);
       std::cout << "Output:\n\t" << output << "\n";
     }
   }

src/ort_genai.h

@@ -4,10 +4,13 @@
 #pragma once
 
 #include <memory>
-#include "span.h"  // TODO Use the std span header if we can assume C++20.
 #include <stdexcept>
 #include <type_traits>
 
+#if __cplusplus >= 202002L
+#include <span>
+#endif
+
 #include "ort_genai_c.h"
 
 // GenAI C++ API
@@ -92,9 +95,19 @@ struct OgaSequences : OgaAbstract {
     return OgaSequencesCount(this);
   }
 
+  size_t SequenceCount(size_t index) const {
+    return OgaSequencesGetSequenceCount(this, index);
+  }
+
+  const int32_t* SequenceData(size_t index) const {
+    return OgaSequencesGetSequenceData(this, index);
+  }
+
+#if __cplusplus >= 202002L
   std::span<const int32_t> Get(size_t index) const {
-    return {OgaSequencesGetSequenceData(this, index), OgaSequencesGetSequenceCount(this, index)};
+    return {SequenceData(index), SequenceCount(index)};
   }
+#endif
 
   static void operator delete(void* p) { OgaDestroySequences(reinterpret_cast<OgaSequences*>(p)); }
 };
@@ -110,11 +123,19 @@ struct OgaTokenizer : OgaAbstract {
     OgaCheckResult(OgaTokenizerEncode(this, str, &sequences));
   }
 
+  OgaString Decode(const int32_t* tokens_data, size_t tokens_length) const {
+    const char* p;
+    OgaCheckResult(OgaTokenizerDecode(this, tokens_data, tokens_length, &p));
+    return p;
+  }
+
+#if __cplusplus >= 202002L
   OgaString Decode(std::span<const int32_t> tokens) const {
     const char* p;
     OgaCheckResult(OgaTokenizerDecode(this, tokens.data(), tokens.size(), &p));
     return p;
   }
+#endif
 
   static void operator delete(void* p) { OgaDestroyTokenizer(reinterpret_cast<OgaTokenizer*>(p)); }
 };
@@ -190,9 +211,19 @@ struct OgaGenerator : OgaAbstract {
     OgaCheckResult(OgaGenerator_GenerateNextToken(this));
   }
 
+  size_t GetSequenceLength(size_t index) const {
+    return OgaGenerator_GetSequenceLength(this, index);
+  }
+
+  const int32_t* GetSequenceData(size_t index) const {
+    return OgaGenerator_GetSequence(this, index);
+  }
+
+#if __cplusplus >= 202002L
   std::span<const int32_t> GetSequence(size_t index) const {
-    return {OgaGenerator_GetSequence(this, index), OgaGenerator_GetSequenceLength(this, index)};
+    return {GetSequenceData(index), GetSequenceLength(index)};
   }
+#endif
 
   static void operator delete(void* p) { OgaDestroyGenerator(reinterpret_cast<OgaGenerator*>(p)); }
 };

test/c_api_tests.cpp

@@ -120,21 +120,27 @@ TEST(CAPITests, GreedySearchGptFp32CAPI) {
 
   // Verify outputs match expected outputs
   for (int i = 0; i < batch_size; i++) {
-    auto sequence = generator->GetSequence(i);
+    const auto sequence_length = generator->GetSequenceLength(i);
+    const auto* sequence_data = generator->GetSequenceData(i);
 
-    auto* expected_output_start = &expected_output[i * max_length];
-    EXPECT_TRUE(0 == std::memcmp(expected_output_start, sequence.data(), max_length * sizeof(int32_t)));
+    ASSERT_LE(sequence_length, max_length);
+
+    const auto* expected_output_start = &expected_output[i * max_length];
+    EXPECT_TRUE(0 == std::memcmp(expected_output_start, sequence_data, sequence_length * sizeof(int32_t)));
   }
 
   // Test high level API
   auto sequences = model->Generate(*params);
 
   // Verify outputs match expected outputs
   for (int i = 0; i < batch_size; i++) {
-    auto sequence = sequences->Get(i);
+    const auto sequence_length = sequences->SequenceCount(i);
+    const auto* sequence_data = sequences->SequenceData(i);
+
+    ASSERT_LE(sequence_length, max_length);
 
-    auto* expected_output_start = &expected_output[i * max_length];
-    EXPECT_TRUE(0 == std::memcmp(expected_output_start, sequence.data(), max_length * sizeof(int32_t)));
+    const auto* expected_output_start = &expected_output[i * max_length];
+    EXPECT_TRUE(0 == std::memcmp(expected_output_start, sequence_data, sequence_length * sizeof(int32_t)));
   }
 }