move construct_client_pool into .cpp for accurate return type

Author: joshbsiegel

src/mongocxx/pool.cpp

@@ -33,6 +33,18 @@
 namespace mongocxx {
 MONGOCXX_INLINE_NAMESPACE_BEGIN
 
+// Attempts to create a new client pool using the uri. Throws an exception upon error.
+static mongoc_client_pool_t* construct_client_pool(mongoc_uri_t* uri) {
+    bson_error_t error;
+    auto pool = libmongoc::client_pool_new_with_error(uri, &error);
+    if (error.code) {
+        // If constructing a client pool failed, throw an exception from the bson_error_t.
+        throw_exception<operation_exception>(error);
+    }
+
+    return pool;
+}
+
 void pool::_release(client* client) {
     libmongoc::client_pool_push(_impl->client_pool_t, client->_get_impl().client_t);
     // prevent client destructor from destroying the underlying mongoc_client_t
@@ -43,7 +55,7 @@ void pool::_release(client* client) {
 pool::~pool() = default;
 
 pool::pool(const uri& uri, const options::pool& options)
-    : _impl{stdx::make_unique<impl>((mongoc_client_pool_t*)construct_client_pool(uri))} {
+    : _impl{stdx::make_unique<impl>(construct_client_pool(uri._impl->uri_t))} {
 #if defined(MONGOCXX_ENABLE_SSL) && defined(MONGOC_ENABLE_SSL)
     if (options.client_opts().tls_opts()) {
         if (!uri.tls())
@@ -132,17 +144,5 @@ stdx::optional<pool::entry> pool::try_acquire() {
         entry::unique_client(new client(cli), [this](client* client) { _release(client); }));
 }
 
-void* pool::construct_client_pool(const uri& uri) {
-    bson_error_t error = {};
-    mongoc_client_pool_t* temp_impl =
-        libmongoc::client_pool_new_with_error(uri._impl->uri_t, &error);
-    if (error.code) {
-        // If constructing a client pool failed, throw an exception from the bson_error_t.
-        throw_exception<operation_exception>(error);
-    }
-
-    return temp_impl;
-}
-
 MONGOCXX_INLINE_NAMESPACE_END
 }  // namespace mongocxx

src/mongocxx/pool.hpp

@@ -109,9 +109,6 @@ class MONGOCXX_API pool {
     ///
     stdx::optional<entry> try_acquire();
 
-    // Attempts to create a new client pool using the uri. Throws an exception upon error.
-    void* construct_client_pool(const uri& uri);
-
    private:
     friend class options::auto_encryption;