examples : small code cleanups (#322)

- remove unnecessary initialization of string to ""
- use empty() instead of checking size()
- use emplace_back instead of push_back
- use nullptr instead of NULL
- remove unnecessary call to .data() on string
- use character overload of find_first_of() instead of passing a string

examples/talk/gpt-2.cpp

@@ -40,7 +40,7 @@ std::vector<gpt_vocab::id> gpt_tokenize(const gpt_vocab & vocab, const std::stri
     // find the longest tokens that form the words:
     std::vector<gpt_vocab::id> tokens;
     for (const auto & word : words) {
-        if (word.size() == 0) continue;
+        if (word.empty()) continue;
 
         int i = 0;
         int n = word.size();
@@ -86,7 +86,7 @@ gpt_vocab::id gpt_sample_top_k_top_p(
     logits_id.reserve(n_logits);
 
     for (int i = 0; i < n_logits; i++) {
-        logits_id.push_back(std::make_pair(logits[i], i));
+        logits_id.emplace_back(logits[i], i);
     }
 
     // find the top K tokens
@@ -327,7 +327,7 @@ bool gpt2_model_load(const std::string & fname, gpt2_model & model, gpt_vocab &
     {
         struct ggml_init_params params;
         params.mem_size   = ctx_size;
-        params.mem_buffer = NULL;
+        params.mem_buffer = nullptr;
 
         model.ctx = ggml_init(params);
         if (!model.ctx) {
@@ -448,7 +448,7 @@ bool gpt2_model_load(const std::string & fname, gpt2_model & model, gpt_vocab &
             std::string name(length, 0);
             fin.read(&name[0], length);
 
-            if (model.tensors.find(name.data()) == model.tensors.end()) {
+            if (model.tensors.find(name) == model.tensors.end()) {
                 fprintf(stderr, "%s: unknown tensor '%s' in model file\n", __func__, name.data());
                 return false;
             }
@@ -833,7 +833,7 @@ Me too.
 struct gpt2_context * gpt2_init(const char * path_model) {
     gpt2_context * ctx = new gpt2_context;
 
-    ctx->rng = std::mt19937(time(NULL));
+    ctx->rng = std::mt19937(time(nullptr));
 
     // load the model
     {
@@ -886,7 +886,7 @@ std::string gpt2_gen_text(gpt2_context * ctx, const char * text, int max_tokens)
 
     for (int i = embd.size(); i < (int) embd_inp.size() + n_predict; i++) {
         // predict
-        if (embd.size() > 0) {
+        if (!embd.empty()) {
             if (!gpt2_eval(ctx->model, ctx->n_threads, n_past, embd, embd_w, mem_per_token)) {
                 printf("gpt-2: failed to generate text\n");
                 return "";

examples/talk/talk.cpp

@@ -39,7 +39,7 @@ struct whisper_params {
     std::string model_wsp = "models/ggml-base.en.bin";
     std::string model_gpt = "models/ggml-gpt-2-117M.bin";
     std::string speak     = "./examples/talk/speak.sh";
-    std::string fname_out = "";
+    std::string fname_out;
 };
 
 void whisper_print_usage(int argc, char ** argv, const whisper_params & params);
@@ -588,7 +588,7 @@ int main(int argc, char ** argv) {
 
                 audio.get(params.voice_ms, pcmf32_cur);
 
-                std::string text_heard = "";
+                std::string text_heard;
 
                 if (!force_speak) {
                     text_heard = ::trim(::transcribe(ctx_wsp, params, pcmf32_cur, prob0, t_ms));
@@ -610,7 +610,7 @@ int main(int argc, char ** argv) {
                 text_heard = std::regex_replace(text_heard, std::regex("[^a-zA-Z0-9\\.,\\?!\\s\\:\\'\\-]"), "");
 
                 // take first line
-                text_heard = text_heard.substr(0, text_heard.find_first_of("\n"));
+                text_heard = text_heard.substr(0, text_heard.find_first_of('\n'));
 
                 // remove leading and trailing whitespace
                 text_heard = std::regex_replace(text_heard, std::regex("^\\s+"), "");
@@ -640,18 +640,18 @@ int main(int argc, char ** argv) {
 
                     text_to_speak = gpt2_gen_text(ctx_gpt, prompt.c_str(), params.max_tokens);
                     text_to_speak = std::regex_replace(text_to_speak, std::regex("[^a-zA-Z0-9\\.,\\?!\\s\\:\\'\\-]"), "");
-                    text_to_speak = text_to_speak.substr(0, text_to_speak.find_first_of("\n"));
+                    text_to_speak = text_to_speak.substr(0, text_to_speak.find_first_of('\n'));
 
                     // remove first 2 lines of base prompt
                     if (n_iter > 4) {
                         {
-                            const size_t pos = prompt_base.find_first_of("\n");
+                            const size_t pos = prompt_base.find_first_of('\n');
                             if (pos != std::string::npos) {
                                 prompt_base = prompt_base.substr(pos + 1);
                             }
                         }
                         {
-                            const size_t pos = prompt_base.find_first_of("\n");
+                            const size_t pos = prompt_base.find_first_of('\n');
                             if (pos != std::string::npos) {
                                 prompt_base = prompt_base.substr(pos + 1);
                             }